Cearachelys placidoi Gaffney, Campos, and

GAFFNEY, EUGENE S, TONG, HAIYAN & MEYLAN, PETER A, 2006, EVOLUTION OF THE SIDE-NECKED TURTLES: THE FAMILIES BOTHREMYDIDAE, EURAXEMYDIDAE, AND ARARIPEMYDIDAE, Bulletin of the American Museum of Natural History 300 (300), pp. 1-698 : 56-84

Cearachelys placidoi Gaffney, Campos, and

Hirayama, 2001

TYPE SPECIMEN: MPSC, a partial skull (figs. 70, 71), shell, cervicals, and limb elements.

TYPE LOCALITY: Probably Santana do Cariri, Ceara, Brazil (fig. 13).

HORIZON: Probably Romualdo Member of the Santana Formation, probably Albian in age (ca. 110 mya; Maisey, 1990, 1991).

DEPOSITIONAL ENVIRONMENT: Near-shore marine ( Maisey, 1990) with freshwater episodes ( Maisey, 2000). See Araripemys for more discussion.

DIAGNOSIS: Same as for genus.

ETYMOLOGY: In honor of Dr. Placido Nuvens, Director of the Museu Paleontologico de Santana do Cariri, Ceara, Brazil.

REFERRED MATERIAL: THUg 1798 , nearly complete skeleton with skull (figs. 72, 73), lower jaw, shell (fig. 258C–E), cervicals, and limb elements, near Santana do Cariri , Romualdo Member, Santana Formation, Albian, purchased from von Leonhardt, 1993 ; BSP 1976 I 160, nearly complete skeleton with damaged skull (figs. 74–76), lower jaws (fig. 234), shell (fig. 258A, B), cervicals and limb elements, Juazeiro do Norte , Ceará, Brazil, Santana Formation, probably Albian .

Galianemys Gaffney, Tong, and Meylan, 2002

TYPE SPECIES: Galianemys whitei Gaffney, Tong, and Meylan, 2002 .

INCLUDED SPECIES: G. whitei , G. emringeri .

DISTRIBUTION: Late Cretaceous of Morocco.

ETYMOLOGY: For Henry Galiano, who assisted in obtaining specimens of this and other turtles for the AMNH, and for his lifelong interest and support of paleontology at the AMNH.

REVISED DIAGNOSIS: Bothremydid pleurodires of the tribe Cearachelyini with the unique character of jugal widely retracted from orbital margin by broad contact of postorbital and maxilla. Other differentiating characters are: incisura columellae auris closed not open as in Cearachelys ; cheek with no emargination, not even the slight one seen in Cearachelys ; interorbital distance wider than in Cearachelys ; labial ridge thicker than in Cearachelys ; sulcus olfactorius ridge deeper than in Cearachelys ; antrum postoticum smaller than in Cearachelys ; tuberculum basioccipitale large and shelflike in contrast to small and blunt in Cearachelys ; jugal-palatine contact less extensive than in Cearachelys .

PREVIOUS WORK: Gaffney, Tong, and Meylan (2002) named and described Galianemys , while Lapparent de Broin and Werner (1998) and Lapparent de Broin (2000) referred to an undescribed taxon from Erfoud that is probably Galianemys (see below).

DISCUSSION: Two shells from the Kem Kem beds (described below in the shell section) probably belong to Galianemys . The shells are not identical and may represent the two species seen in the skulls. We have left the shells out of the phylogenetic analysis until associated material becomes available.

The two species of Galianemys are the best known bothremydids, with a number of skulls available for each species (table 9). CT scans of one of the skulls are available online at the University of Texas Digital Imaging website:,http://www.digimorph.org/specimens/ Galianemys emringeri /.. The two species of Galianemys are united by the retracted jugal and other characters that separate them from Cearachelys . However, in the MPC the genus collapses in one step because most of these characters are gradational, hard to determine in the more advanced Bothremydini , and not entered into the dataset. Evidence for the union of the two Galianemys species is actually stronger than expressed in the MPC. See table 7 for comparison of the species of the Cearachelyini .

Galianemys emringeri Gaffney, Tong, and

Meylan, 2002

TYPE SPECIMEN: AMNH 29985 , a skull (figs. 85, 86, 278) lacking most of the right triturating area, both cheeks, and the left otic chamber ; donated by Henry Galiano.

TYPE LOCALITY: Near al Taouz, province de Kasr-es-Souk, Morocco (figs. 14, 15).

HORIZON: Cenomanian, Kem Kem beds.

DEPOSITIONAL ENVIRONMENT: Deltaic or fluvial ( Sereno et al., 1996; Cavin et al., 2001), found with dinosaurs and other freshwater/terrestrial fauna.

DIAGNOSIS: A species of Galianemys differing from Galianemys whitei by having a prefrontal-frontal suture convex anteriorly rather than straight; small or absent jugal-palatine contact; jugal not exposed on triturating surface; triturating surface flat; labial ridge relatively thicker; antrum postoticum relatively larger; prootic exposed ventrally containing foramen nervi facialis; deep fossa pterygoidea; foramen nervi vidiani exposed ventrally; and foramen posterius canalis carotici interni formed mostly by basisphenoid with only slight or no contribution from pterygoid ( Gaffney, Tong, and Meylan, 2002).

ETYMOLOGY: In recognition of Gilles Emringer for helping obtain Kem Kem specimens.

REFERRED MATERIAL: AMNH 30026, partial braincase, Kem Kem, Morocco, donated by Henry Galiano; AMNH 30035, nearly complete skull (figs. 83, 84, 87, 284B), Kem Kem, Morocco, donated by Gilles Emringer and François Escuillie´; AMNH 30037, skull lacking right cheek (fig. 88), Kem Kem, Morocco, donated by Michael Hammer; AMNH 30040, nearly complete skull, donated by Michael Hammer; MDEt 46, partial braincase, Kem Kem, Morocco.

DISCUSSION: See table 7 for comparison with Galianemys whitei and table 9 for variation among Galianemys specimens.

TABLE 9

Comparison of Galianemys Specimens

Galianemys whitei Gaffney, Tong, and

Meylan, 2002

TYPE SPECIMEN: AMNH 29987, nearly complete skull (figs. 91, 92, 99, 284A), donated by Mr. Richard White.

TYPE LOCALITY: Near Al Taouz, Province de Kasr-es-Souk, Morocco (figs. 14, 15).

HORIZON: Cenomanian, Kem Kem beds.

DEPOSITIONAL ENVIRONMENT: Deltaic or fluvial (Cavin et al., 2001; Sereno et al., 1996), found with dinosaurs and other freshwater/terrestrial fauna.

DIAGNOSIS: A species of Galianemys differing from Galianemys emringeri by having a straight rather than curved prefrontal-frontal suture; a relatively larger jugal-palatine contact; jugal exposed on triturating surface; small depression on posteroventral part of triturating surface; labial ridge relatively thinner; antrum postoticum usually relatively smaller; prootic not exposed ventrally; shallow or absent fossa pterygoidea; foramen nervi vidiani not exposed; and foramen posterius canalis carotici formed by basisphenoid and pterygoid equally ( Gaffney, Tong, and Meylan, 2002).

ETYMOLOGY: For Richard S. White, who brought a number of specimens to our attention and aided our work.

REFERRED MATERIAL: AMNH 29986, skull lacking left orbital region and palate (figs. 93, 94, 98), near Al Taouz, Province de Kasr-es-Souk, Morocco, donated by Richard S. White; AMNH 30027, skull lacking left orbital region and palate (figs. 100, 284C), ‘‘Kem Kem’’, Morocco, donated by François Escuillie´; AMNH 30028, nearly complete skull, ‘‘Kem Kem’’, Morocco, donated by François Escuillie´; AMNH 30036, nearly complete skull (fig. 280), ‘‘Kem Kem’’, Morocco, donated by Michael Hammer; MDEt 45, skull lacking basicranium with quadrate incorrectly attached, Kem Kem, Morocco; AMNH 30555, nearly complete skull (figs. 95, 96), Kem Kem, Morocco, donated by François Escuillie´.

DISCUSSION: A specimen of what appears to be Galianemys whitei was figured in Lapparent de Broin and Werner (1998: fig. 4a, e) as ‘‘new bothremydid form, Hammada [sic] du Guir, East of Erfoud, Morocco, Albian, MNHN (P) MRS 2098, Fectay coll.’’ In the text ( Lapparent de Broin and Werner, 1998: 10) it is characterized as ‘‘A new bothremydid form, Albian of Morocco (that can be positioned early in the family development) …’’. No other information is provided, but the general shape and retracted jugal indicate Galianemys . The jugal on the triturating surface and the thin labial ridge suggest Galianemys whitei , but the area around the foramen posterius canalis carotici interni is too roughly drawn to determine the extent of the fossa pterygoidea or the exposure of the prootic, if any.

See table 7 for comparison with Galianemys emringeri and table 9 for variation among Galianemys specimens.

INFRAFAMILY BOTHREMYDODDA BAUR,

1891, NEW RANK

TYPE GENUS: Bothremys Leidy, 1865 .

INCLUDED GENERA: Foxemys Tong, Gaffney, and Buffetaut, 1998 ; Polysternon Portis, 1882 ; Elochelys Nopcsa, 1931 ; Zolhafah Lapparent de Broin and Werner, 1998 ; Rosasia Carrington da Costa, 1940 ; Araiochelys , n. gen.; Bothremys Leidy, 1865 ; Chedighaii , n. gen.; Taphrosphys Cope, 1869a ; Labrostochelys , n. gen.; Phosphatochelys Gaffney and Tong, 2003 ; Ummulisani , n. gen.; Rhothonemys , n. gen.; Azabbaremys Gaffney, Moody, and Walker, 2001 ; Nigeremys Broin, 1977 ; Arenila Lapparent de Broin and Werner, 1998 .

DIAGNOSIS: Members of the subfamily Bothremydinae with the following unique characters within the Bothremydidae : quadrate shelf formed below cavum tympani (unique among all turtles); foramen stapedio-temporale and foramen nervi trigemini very close on anterior face of otic chamber (unique among all turtles); and condylus occipitalis and neck formed only of exoccipitals (also occurs in Pelomedusidae ). Other differentiating characters are: fenestra postotica closed (also in Kurmademys ); plastron with anterior margin posterior to the carapace margin; and short and wide anterior lobe.

DISCUSSION: The sister-group relationship of the Bothremydini and the Taphrosphyini is well supported in the phylogenetic analysis with a number of unambiguous characters (fig. 288). The principal weakness in this grouping is Foxemys and Polysternon , which have an open incisura columellae auris and cause a collapse of resolution in the Bothremydini and Bothremydodda with increased decay steps. The removal of these genera from the Bothremydodda to a sister-group relationship with the remaining ‘‘higher’’ bothremydids is a possibility that should be kept in mind. If some of the characters uniting the Bothremydini , particularly those related to the expanded snout and large triturating surfaces, were considered as plesiomorphic, then the Bothremydodda would partially collapse, resulting in a cladogram like that in figure 289.

TRIBE BOTHREMYDINI , NEW

TYPE GENUS: Bothremys Leidy, 1865 .

INCLUDED GENERA: Foxemys Tong, Gaffney, and Buffetaut, 1998 ; Polysternon Portis, 1882 ; Elochelys Nopcsa, 1931 ; Zolhafah Lapparent de Broin and Werner, 1998 ; Rosasia Carrington da Costa, 1940 ; Araiochelys , n. gen.; Bothremys Leidy, 1865 ; Chedighaii , n. gen.

DIAGNOSIS: Bothremydid pleurodires with the following unique characters: preorbital part of skull very broad (except in Araiochelys ); fenestra interorbitale low; other differentiating characters are: temporal emargination moderate, in contrast to slight to absent in Taphrosphyini and deep in Kurmademydini and Cearachelyini ; jugal-quadrate contact absent; supraoccipital-quadrate contact present (except in Zolhafah ), in contrast to Taphrosphyini ; palatine forms greater part of triturating surfaces than it does in Taphrosphyini ; triturating surfaces very wide (except in Araiochelys ); shell surface with ‘‘pelomedusoid ornamentation’’ consisting of fine forking and irregular vascular grooves; humeropectoral sulcus on epihyoplastral suture ( Foxemys and Polysternon ) or posterior to it ( Rosasia , Araiochelys , Chedighaii ), and crossing entoplastron (except Rosasia ); pectoroabdominal sulcus near or on mesoplastron (except Araiochelys ); pubic scar oval and wider than in Taphrosphys ; ischiac scar triangular and not near the xiphiplastral edge.

DISCUSSION: This tribe is roughly equivalent to the ‘‘ Bothremys group’’ (also ‘‘Groupe Bothremys ,’’ ‘‘ Bothremys Leidy 1865 group’’) of Antunes and Broin (1988), Lapparent de Broin and Werner (1998), Lapparent de Broin and Murelaga (1999), and Lapparent de Broin (2000a), an informal assemblage consisting of Zolhafah , Rosasia , and Bothremys . Other authors ( Gaffney, Campos, and Hirayama, 2001; Gaffney, Chatterjee, and Rudra, 2001; Gaffney, Tong, and Meylan, 2002) have used this informal grouping and expanded it to include newly described taxa. However, Lapparent de Broin (2000b) also used the term ‘‘pre- Bothremys group’’ for Polysternon plus what we refer to as Foxemys (‘‘ Polysternon mechinorum ’’ in the usage of Lapparent de Broin 2000b). The ‘‘pre- Bothremys group’’ would be the same as our subtribe Foxemydina .

A lower jaw, AMNH 29989 (figs. 245, 246), is probably a tribe Bothremydini based on its close similarity to the lower jaws of Bothremys . This specimen is from the Ypresian phosphates of couche 1, Ouled Abdoun Basin, Morocco. It probably represents a different genus from the bothremydines described here because of its very deep processus coronoideus.

Most members of the tribe have distinctive pits on the triturating surfaces (figs. 237– 246). Gaffney and Zangerl (1968: 235–236) discussed the possible function of these pits in Bothremys cooki :

The function of the large palatal and mandibular pits in Bothremys has been commented on by earlier authors. Leidy (1865, p. 111) wrote, ‘The function of the latter (the pit) … is difficult to comprehend. It does not appear to be an alveolus for a tooth; but probably it may have accommodated a corneous tooth-like process springing from a corresponding hollow of the lower jaw.’’ Baur (1891, pp. 423–424) suggested the presence of ‘‘a large tusk’’ in the pits. Hay (1908, p. 104) believed that the tooth idea was improbable and made another suggestion: ‘‘The whole construction of the skull of Bothremys indicates that it was accustomed to crush hard objects as food. Probably these objects were of such a nature that economy of force demanded that they should be brought to a particular spot on the jaw for crushing. To provide for the rapid reproduction of the horn beneath these areas for crushing, these pits became developt in a way analogous to the human ‘nailbed.’’’

Before discussing the merits of these ideas, the morphology of the structures involved should be summarized. There are two pits in the palate, principally formed by the jugals, but all of the surrounding bones including the cheek are modified to form the pits. Each pit is thickest (see cross-section) about midway in the cone. The triturating surfaces occupy most of the palate and have an overall form of two funnels opening ventrally. The lower jaws have matching structures which, however, do not open directly upward into the jugal pits, but open dorso-anteriorly.

Hay was almost certainly right in thinking that Bothremys was toothless. The ‘‘corneous toothlike process’’ of Leidy has a somewhat greater possibility; however, the horny covering of recent turtles rarely forms a structure that is not present in the underlying bone. Thicknesses vary, but whole structures, like a large tusk, are not known to occur independent of an osseous core. Therefore, it seems likely that the whole triturating surface was covered by horny material, thickest in the tips of the pits but not forming tusk-like structures.

This inference is most like the suggestion of Hay previously quoted. However, Hay also thought that the pits were areas of rapid horn production and were not expressed on the external surface. It would be difficult to disprove this, but it is more probable that the pits were expressed as depressions in the external horny covering as in living turtles.

If this latter suggestion were correct, the pits might function to crack hard objects, slightly larger than the pits, which otherwise would be difficult to grasp or hold onto by means of a ‘‘normal’’ triturating surface. Certain ovoid mollusks (gastropods?) might comprise the food of Bothremys . There is a disadvantage to this hypothesis since it seems to mean that a particular individual of Bothremys would be limited to objects of a certain size range, because larger or smaller ones could not fit the pits. The crushing function of the pits is substantiated by other structural evidence. High and well-developed coronoid processes, as in Bothremys …, are characteristic of turtles with crushing habits (see Stejneger, 1944, plate 30, for an example in Amyda ). The posterior position of the articulation and the position of the pits immediately adjacent to the coronoid processes result in an efficient crushing mechanism with the adductor musculature attached close to the object to be crushed, but far from the fulcrum.

This discussion, suggesting that the pits served for grasping and crushing slippery mollusks, still seems the best guess at present. The recent discovery that the pit morphology is much more widespread taxonomically than known in 1968 only serves to reinforce the general utility of the pit structure, whatever it was, despite the fact that no living turtle still has the pits.

See table 5 for a comparison of the tribes of the Bothremydidae and table 10 for a comparison of the genera in the tribe Bothremydini .

SUBTRIBE FOXEMYDINA , NEW

TYPE GENUS: Foxemys Tong, Gaffney, and Buffetaut, 1998 .

INCLUDED GENERA: Foxemys Tong, Gaffney, and Buffetaut, 1998 ; Polysternon Portis, 1882 ; Elochelys Nopcsa, 1931 .

DIAGNOSIS: Members of the tribe Bothremydini with the following characters contrasting with Bothremydina : maxilla-quadrate contact absent; triturating surface without maxillary pits (also in Chedighaii ); dentary pits absent; jugal not exposed on triturating surface (also in Chedighaii ); stapes not contained in bony canal; fossa pterygoidea deep and narrow; foramen jugulare posterius only partially closed; basisphenoid ventral outline pentagonal; pectoral scales extending onto epiplastron.

DISCUSSION: We have chosen Foxemys as the type genus for this taxon, as it is skull based, in contrast to Polysternon , in which the skull is not definitely associated with the type shell. This subtribe is essentially the same as the ‘‘pre- Bothremys group’’ of Lapparent de Broin (2000b).

Foxemys Tong, Gaffney,

and Buffetaut, 1998

TYPE AND ONLY INCLUDED SPECIES: Foxemys mechinorum Tong, Gaffney, and Buffetaut, 1998 .

DISTRIBUTION: Late Cretaceous Late Campanian–Early Maastrichtian of France.

ETYMOLOGY: From the name of the locality, Fox Amphoux, in southern France ( Tong et al., 1998).

REVISED DIAGNOSIS: A bothremydid pleurodire of the subtribe Foxemydina with

TABLE 10

Genera of Bothremydini

TABLE 10

Continued the following characters differentiating it from Polysternon : fossa pterygoidea deeper than in Polysternon ; orbital rim low, as in Bothremys , not high, as in Polysternon ; triturating surfaces very wide, as in Bothremys and Chedighaii , in contrast to narrower, as in Polysternon ; condylus mandibularis close to level of condylus occipitalis, as in most Bothremydini but in contrast to Polysternon ; shell similar to Polysternon but lacking the parallel striations and nuchal emargination seen in Polysternon ; relatively large intergular scale; straight lateral border of posterior lobe of the plastron and a wide anal notch, in contrast to Polysternon .

DISCUSSION: Lapparent de Broin (2001: 169) synonymized the genus Foxemys with the genus Polysternon while recognizing the distinctness of the species Foxemys mechinorum . Her rationale seemed to be that the shells are very similar and therefore belong in the same genus. Our phylogenetic analysis shows Foxemys and Polysternon as sister taxa and belonging in the same monophyletic group, whether it is a genus or other higher category. The recognition of genera is subjective, as long as they are monophyletic, so it is basically a matter of convention and taste, not science. Interestingly, Lapparent de Broin and Werner (1998) erected a new genus, Arenila , for a skull very similar to a previously known taxon, Nigeremys , both of which could be included in the same genus. We choose to take a more split view of the situation and recognize Foxemys as well as Arenila . In our subjective view, this is more consistent with most other genera in pleurodires, as things stand at present. Furthermore, recognition of both Foxemys and Polysternon allows the expression of the sister-group relationship of these species without resorting to subgenera. In any case, other than monophyly, there are no objective criteria for the recognition of genera, and it is a matter of taste and consent.

Botfalvai (2005) announced in an abstract the discovery of two skulls and other elements from the Santonian of Hungary as new but unnamed bothremydids similar to Foxemys .

See table 10 for a comparison of genera of the tribe Bothremydini .

Foxemys mechinorum Tong, Gaffney, and

Buffetaut, 1998

TYPE SPECIMEN: MDEt 10 , a dorsoventrally crushed skull with right half of carapace and complete plastron (figs. 105, 106; Tong et al., 1998: figs. 1, 2) .

TYPE LOCALITY: Fox Amphoux, southern France (fig. 14).

HORIZON: Late Campanian–Early Maastrichtian, Late Cretaceous.

DEPOSITIONAL ENVIRONMENT: The Massecaps locality, Cruzy, Hérault, France, has yielded very abundant Foxemys and other vertebrate remains, and it appears to be freshwater in origin. ‘‘The vertebrates are scattered through a thickness of about 1 m of variegated clays which sometimes contain iron oxide nodules, and are cut by unfossiliferous sandy channels. It would appear to be a floodplain deposit’’ ( Buffetaut et al., 1999).

DIAGNOSIS: Same as for genus.

ETYMOLOGY: For discoverers of the material, Patrick and Annie Méchin.

REFERRED MATERIAL: From the Fox Amphoux locality: an almost complete skull (figs. 103, 104, 107, 281; PAM 511 A, Tong et al., 1998: figs. 3–6); an incomplete lower jaw (figs. 235, 236; PAM 511 B, Tong et al., 1998: figs. 7, 8); an almost complete and well-preserved shell in which the plastron is complete and only the posterior part of the carapace is missing (lacking right sixth to eighth costal and part of seventh and eighth left costal bones, eighth to eleventh right peripheral and eleventh left peripheral bones, suprapygal and pygal bones; PAM 548, Tong et al., 1998: figs. 9, 10); a partial shell consisting of the anterior third of the carapace in poor condition and a complete plastron (MDEt 09, Tong et al., 1998: fig. 11); a right scapula-coracoid (MDEt 11); and several isolated plates, an almost complete shell, MHNM uncataloged; Late Campanian–Early Maastrichtian, Var, France.

From the Massecaps locality: MC M2114– M2118, all lower jaws; MC M1734, nearly complete skull; MC M2119, a partial skull, Late Campanian–Early Maastrichtian, Cruzy, Herault, France ( Foxemys is the most abundant form among vertebrates from this locality, including one complete and one partial skull, several lower jaws, hundreds of disarticulated and isolated plates, vertebrae, girdles and limb bones; Buffetaut et al., 1999).

From the Montplo locality: MC uncataloged, shell, Cruzy, France, Late Campanian–Early Maastrichtian.

From the Bellevue locality: MDEt C3 774, partial skull and shell fragments, Campagne sur Aude, Aude, France, Late Campanian– Early Maastrichtian.

PREVIOUS WORK: Foxemys has been described and figured in Tong et al. (1998), in which they described the skull and shell.

DISCUSSION: The Fox Amphoux vertebrates come from sandstones and clays similar to those known in the Aix-en- Provence Basin, farther west, as the lower part of the Rognacian. This local stage is probably a nonmarine equivalent of the type Maastrichtian stage on the basis of magnetostratigraphy ( Westphal and Durand, 1990). The Fox Amphoux vertebrate assemblage is thus probably of early Maastrichtian age ( Buffetaut and Le Loeuff, 1991). This is in agreement with the composition of its fauna, in which the dominant dinosaurs are titanosaurids and the ornithopod Rhabdodon . As shown by Le Loeuff et al. (1994), such assemblages characterize the early part of the Maastrichtian in southern France, whereas late Maastrichtian assemblages are dominated by hadrosaurid dinosaurs, which have not been reported from Fox Amphoux.

Besides turtles, the Fox Amphoux vertebrate assemblage includes hybodont sharks, a Lepisosteus -like actinopterygian, alligatorid and crocodylid crocodilians, theropods (including a dromaeosaurid and a possible abelisaurid), titanosaurid sauropods, ornithopods ( Rhabdodon ), ankylosaurs, and large flightless birds ( Buffetaut et al., 1997).

In addition to Foxemys , two pleurodires are known from Late Cretaceous localities in southern France. Polysternon provinciale ( Matheron, 1869) is known from a large series of shells and a skull, while Elochelys perfecta ( Nopcsa, 1931) and E. convenarum Laurent, Tong, and Claude, 2002 are known only from a few shells. Elochelys differs from Foxemys in its smaller size (carapace length of 20–25 cm for E. perfecta and 35 cm for E. convenarum ), the apparent lack of a suprapygal bone (in E. perfecta only), and an intergular scute that completely separates the humeral scutes ( Nopcsa, 1931; Broin, 1977; Laurent et al., 2002). The shell of Foxemys is similar to that of Polysternon provinciale , although there are significant differences ( Tong and Gaffney, 2000: table 1). The recently described skull of Polysternon provinciale ( Tong and Gaffney, 2000) is also similar to the skull of Foxemys , but again there are significant differences, particularly in the relative positions of the mandibular and occipital condyles.

According to the description of Polysternon atlanticum ( Lapparent de Broin and Murelaga, 1996) , this species from the Late Cretaceous of northern Spain differs from Foxemys in being much smaller and in having a narrow first vertebral scute.

Another skull that appears to be Foxemys mechinorum, MC M1734 , agrees with PAM 511A and MDEt 10 except that it has a well-developed accessory ridge extending from the anterior midline concavity on the premaxilla, posterolaterally along the maxilla paralleling the labial ridge. Accessory ridges are nearly absent in bothremydids, being found only in Sankuchemys and the undescribed CNRST-SUNY 199. MC M1734 does not seem to have other differences from the two described Foxemys skulls, so it is unclear whether it is best interpreted as individual variation or a new taxon. It also could be the skull of Elochelys , a shell-only genus similar to Foxemys .

Polysternon Portis, 1882

Elochelys Nopcsa, 1931 , in part (only the species ‘‘ E. major ’’).

TYPE SPECIES: Pleurosternon provinciale Matheron, 1869 .

INCLUDED SPECIES: P. provinciale , P. atlanticum .

DISTRIBUTION: Late Cretaceous, Europe.

ETYMOLOGY: Not specified by original author. Translated it could mean ‘‘many, chest’’.

REVISED DIAGNOSIS: A bothremydid pleurodire of the subtribe Foxemydina with the following characters differentiating it from Foxemys : fossa pterygoidea present but not as deep as in Foxemys ; condylus mandibularis anterior to main body of basisphenoid and well anterior to condylus occipitalis; orbital rim high in contrast to Foxemys ; triturating surfaces triangular and wider than in Taphrosphyini but narrower than in Foxemys , Bothremys , and Chedighaii ; shell similar to Foxemys but with parallel striations on the carapace, nuchal emargination present, round lateral borders of posterior lobe of plastron, and a narrow anal notch.

PREVIOUS WORK: The genus Polysternon was erected by Portis in 1882 on the basis of the posterior portion of a shell from the Late Cretaceous of the Fuveau Basin, southeastern France. Portis (1882) also referred two shell fragments, including an anterior portion of carapace, to the genus Polysternon , as well as material earlier described as Pleurosternon provinciale by Matheron (1869) from the same basin. Unfortunately, Matheron did not figure any specimens. The material described by Portis (1882) is now housed in the Musée Cantonal de Géologie de Lausanne, Switzerland. In 1931, Nopcsa studied four turtle shells from the Late Cretaceous of southern France in the Musée d’Histoire Naturelle de Marseille, and reviewed Matheron’s and Portis’ materials. He recognized Polysternon and erected a new genus, Elochelys , including two species, E. major and E. perfecta ( Nopcsa, 1931) . Later, Broin (1977) studied the Late Cretaceous and Tertiary continental turtle faunas of France and synonymized Elochelys major Nopcsa, 1931 and Polysternon provinciale ( Matheron, 1869) . All these are based on shell material. Foxemys mechinorum ( Tong et al., 1998) was the first pleurodiran turtle from the Late Cretaceous of southern France described on the basis of both skull and shell material. The skull figured and referred to Polysternon provinciale in Buffetaut et al. (1996) and Lapparent de Broin and Werner (1998: fig. 4) was described in detail by Tong and Gaffney (2000).

DISCUSSION: The separation of Polysternon from Foxemys is discussed above. See table 10 for a comparison of genera of the tribe Bothremydini .

Polysternon provinciale ( Matheron, 1869)

Pleurosternon provinciale Matheron, 1869 . Polysternon provinciale Portis, 1882 . Polysternum provinciale ( Matheron, 1869) in

Nopcsa, 1931. Elochelys major Nopcsa, 1931 .

TYPE SPECIMEN: MHNM 1982-853 , collection Matheron, anterior portion of carapace, designated as a lectotype in Broin (1977: 37, fig. 1; pl. 1, fig. 3) .

TYPE LOCALITY: ‘‘Lignite de la Grande Mène, Bassin de Fuveau, France’’ ( Broin, 1977).

HORIZON: Campanian, Late Cretaceous.

DEPOSITIONAL ENVIRONMENT: The best P. provinciale material (complete skull and shell) is from the Villeveyrac quarries, located about 20 km southwest of Montpellier (Hérault, France). The vertebrate fauna comes from the lower series of the Late Cretaceous beds, which are Early Campanian dark clays. It includes fishes (Ginglymodi and Teleostei), frogs, turtles, lizards, crocodiles, and dinosaurs (theropods, iguanodonts, and ankylosaurs). Turtle remains are mainly abundant shell fragments; they include both the bothremydid Polysternon provinciale and the cryptodire Solemys . The paleoecology of the vertebrate-bearing Late Cretaceous beds of Villeveyrac has been reconstructed on the basis of sedimentological and paleontological studies that indicate an estuarine landscape combining freshwater and brackish environments (see Buffetaut et al., 1996).

DIAGNOSIS: As for genus.

ETYMOLOGY: Not specified by original author, but presumably the reference is to Provence, France.

REFERRED MATERIAL: AE 28 (Costa Collection), skull (figs. 110–112) described by Tong and Gaffney (2000), figured by Buffetaut et al. (1996: fig. 5) and Lapparent de Broin and Werner (1998), Villeveyrac locality, Hérault, France; a complete shell uncataloged, Costa Collection ( Buffetaut et al., 1996: fig. 4), Villeveyrac, Hérault, France; MDEt collection: shell fragments, same locality; partial plastron and isolated plates ( Tong et al. 1993: figs. B–D), Monséret locality, France; MHNM collection: two shell fragments including an anterior portion of carapace, Fuveau Basin, Campanian, from ‘‘lignite de la grande Mène’’, Fuveau Basin, France ( MHNM 1982-853, Matheron collection; Matheron, 1869; Broin, 1977: fig. 1, pl. 1, fig. 3a, b; the other specimen was lost by the time Broin reviewed the material in 1977); partial shell (collection of the ‘‘Musée Cantonal de Géologie de Lausanne’’, Portis, 1882); holotype of ‘‘ Elochelys major ’’ ( MHNM 1982-857; Nopcsa, 1931: pl. XIII; Broin, 1977: fig. 2, pl. 1, fig. 1); internal cast showing the plastron with pubic and ischiac scars ( MHNM 1982- 855, collection Comte de Gérin-Ricard; Nopcsa, 1931: fig. 1; Broin, 1977: pl. 1, fig. 2); from ‘‘Valdonne’’, Fuveau Basin, France.

DISCUSSION: The identification of the skull from Villeveyrac as Polysternon provinciale is based solely on the occurrence of the skull in the same formation and geographic region as shells of P. provinciale ( Buffetaut et al., 1996) . However, we follow Buffetaut et al. (1996), Lapparent de Broin and Werner (1998), and Tong and Gaffney (2000) who all identified this skull as Polysternon provinciale . It is of course possible that further discoveries will alter this provisional identification. Nonetheless, we think that this course is preferable to naming a new taxon or to not identifying the skull at all. In any case, both skull and shells are bothremydids.

Pleurodiran shell fragments are frequent in the Late Cretaceous localities of southern France. They are usually referred to Polysternon ( Broin, 1977; Lapparent de Broin and Murelaga, 1999; Lapparent de Broin, 2001). However, as several genera of Pleurodira are present in the Late Cretaceous of that region, some of them might belong to Foxemys or Elochelys .

Polysternon atlanticum Lapparent de Broin and Murelaga, 1996

TYPE SPECIMEN: Museo de Ciencias Naturales de Alava, Vitoria: Gasteiz number 6316 ( Lapparent de Broin and Murelaga, 1996: fig. 2C; 1999: pl. 5, fig. 1), an isolated nuchal bone .

TYPE LOCALITY: Laño, Condado de Treviño, Spain ( Lapparent de Broin and Murelaga, 1996, 1999).

HORIZON: Late Campanian ( Lapparent de Broin and Murelaga, 1996, 1999).

DEPOSITIONAL ENVIRONMENT: Alluvial ( Lapparent de Broin and Murelaga, 1996, 1999).

DIAGNOSIS: ‘‘Differs from the type species P. provinciale , from Fuveau, by the smaller shell (11 to 32 cm long), the vertebral 1 narrowest (not covering all the nuchal posterior border or slightly wider than the nuchal posterior border, not much wider) and the absence of the very thin striation of parallel streaks on the dorsal carapace’’ ( Lapparent de Broin and Murelaga, 1996).

ETYMOLOGY: From the Atlantic area ( Lapparent de Broin and Murelaga, 1996).

REFERRED MATERIAL: Over 200 shell fragments, some described in Lapparent de Broin and Murelaga (1999).

PREVIOUS WORK: Two papers describe P. atlanticum : Lapparent de Broin and Murelaga (1996) and Lapparent de Broin and Murelaga (1999).

DISCUSSION: This species seems to be more similar to Foxemys than to Polysternon by the absence of obvious parallel striations on the carapace, the less rounded lateral margins of the posterior lobe of the plastron, and the wider anal notch. The type is a nuchal; it is (barely) diagnosable because it consists of a large number of other disarticulated shell elements, presumed to be from the same taxon.

Elochelys Nopcsa, 1931

TYPE SPECIES: Elochelys perfecta Nopcsa, 1931 .

INCLUDED SPECIES: E. perfecta , E. convenarum .

DISTRIBUTION: Late Cretaceous of southern France.

ETYMOLOGY: Not indicated in Nopcsa, 1931. Elos, Greek for swamp, and chelys, Greek for turtle.

REVISED DIAGNOSIS: Carapace without nuchal notch, with ‘‘pelomedusoid’’ surface texture (weak granulated polygons), in contrast to strong granulated polygons of Taphrosphys ; six or seven neurals; short and broad anterior plastral lobe and small anal notch; large intergular scale completely separating gulars and humerals, reaching pectorals as in Taphrosphys and Ummulisani , but in contrast to all other bothremydids; humeropectoral sulcus mainly anterior to the epihyoplastral suture except the lateral end in contrast to other bothremydids, and crossing entoplastron, as in Taphrosphys , Araiochelys , Chedighaii , Polysternon , and Foxemys , in contrast to Cearachelys and Rosasia ; pectoroabdominal sulcus anterior to mesoplastron, as in Araiochelys and Kurmademys , in contrast to Chedighaii .

PREVIOUS WORK: The genus Elochelys was erected by Nopcsa in 1931 on the basis of shell materials from the Campanian of Fureau Basin in southern France, and included originally two species: E. major and E. perfecta ( Nopcsa, 1931) . Later, Broin (1977) synonymized E. major with Polysternon provinciale . Elochelys is discussed in Antunes and Broin (1988), Lapparent de Broin and Werner (1998), and Lapparent de Broin and Murelaga (1999).

DISCUSSION: Elochelys includes two species, both consisting only of shells. According to Broin (1977), Antunes and Broin (1988), Lapparent de Broin and Werner (1998), and Lapparent de Broin and Murelaga (1999), Elochelys is closely related to Taphrosphys . This is mainly based on the large intergular scale reaching the pectoral scales, the character shared only with Taphrosphys and Ummulisani among the Bothremydidae . Despite the numerous missing data for Elochelys , our analysis identifies three characters that support placement of Elochelys in the subtribe Polysternina : narrow peripheral 1– costal 1 contact, pectoral scales reach epiplastra, and pectoral scales anterior to mesoplastra. Nonetheless, this taxon is not well established, and its phylogenetic position might need to be revised if more material, particularly cranial, becomes available.

In addition to E. perfecta and E. convenarum , some shell fragments from the Late Campanian–earliest Maastrichtian of Laño (northern Spain) and the Early Maastrichtian of Fox Amphoux (southern France) have been referred to? Elochelys sp. ( Lapparent de Broin and Murelaga, 1999).

Elochelys perfecta Nopcsa, 1931

TYPE SPECIMEN: MHNM 1982-852 , Gérin-Ricard collection ; Nopcsa, 1931: pl. XII.

TYPE LOCALITY: Fureau Basin, southern France.

HORIZON: Campanian, Late Cretaceous.

DEPOSITIONAL ENVIRONMENT: Freshwater ( Broin, 1977).

REVISED DIAGNOSIS: A species of Elochelys differing from E. convenarum in smaller size of shell, nuchal bone with longer anterior margin; first peripheral with longer posterior margin; suprapygal absent; first marginal scale wider than long; first vertebral scale narrower than the second vertebral and with nearly parallel lateral margins; second and third vertebral scales wider than long; plastron wide with rounded anterior margins; intergular narrower posteriorly.

ETYMOLOGY: Not known.

REFERRED MATERIAL: An anterior part of a shell ( MHNM 1982-851, Matheron collection; Nopcsa, 1931; Broin, 1977).

PREVIOUS WORK: The genus Elochelys was erected by Nopcsa in 1931 on the basis of shell materials from the Campanian of Fureau Basin in southern France, and originally included two species: E. major and E. perfecta ( Nopcsa, 1931) . E. perfecta was based on two specimens, one complete shell (holotype, MHNM 1982-852, Gérin-Ricard collection; Nopcsa, 1931: pl. 12) and an anterior part of a shell ( MHNM 1982-851, Matheron collection) ( Nopcsa, 1931; Broin, 1977).

Elochelys convenarum Laurent, Tong, and Claude, 2002

TYPE SPECIMEN: A nearly complete shell

( MDEt Cas2-259).

TYPE LOCALITY: Cassagnau 2, Marignac-

Laspeyres, Haute-Garonne, Petites Pyrénées,

southern France.

HORIZON: Marnes d’Auzas Formation, Late Maastrichtian, Late Cretaceous.

DEPOSITIONAL ENVIRONMENT: Fluvio-lagoonal.

DIAGNOSIS: A species of Elochelys differing from E. perfecta in having a larger shell; nuchal plate wider than long with very short anterior margin and strongly expanded posterior part; first peripheral plate with very short posterior margin; suprapygal plate present; first marginal scute square-shaped, covering more than half length of nuchal plate; first vertebral scute wider anteriorly with lateral margin lying on lateral part of first peripheral; second and third vertebral scutes roughly as long as wide; anterior lobe of the plastron with nearly straight anterior margin; intergular very wide posteriorly; shorter intergulo-humeral sulcus and longer intergulo-pectoral sulcus ( Laurent et al., 2002).

ETYMOLOGY: From the Convenes, an ancient people of Gaul who lived in the region ( Laurent et al., 2002).

REFERRED MATERIAL: None.

PREVIOUS WORK: Laurent et al. (2002) described a nearly complete shell as the type specimen of E. convenarum , which is the only specimen of this species.

DISCUSSION: Although there are differences from Elochelys perfecta , the validity of this species should be considered in light of the fact that there is only one specimen and the characters are likely to be subject to individual variation.

SUBTRIBE BOTHREMYDINA , NEW

TYPE GENUS: Bothremys Leidy, 1865 .

INCLUDED GENERA: Zolhafah Lapparent de Broin and Werner, 1998 ; Rosasia Carrington da Costa, 1940 ; Araiochelys , n. gen.; Bothremys Leidy, 1865 ; Chedighaii , n. gen.

DIAGNOSIS: Members of the tribe Bothremydini with the following characters contrasting with Foxemydina : maxilla-quadrate contact present (except in Chedighaii ); triturating surface with maxillary pits (except Chedighaii ); dentary pits present; jugal widely exposed on triturating surface (except Chedighaii ); incisura columellae auris closed and stapes contained in bony canal; fossa pterygoidea absent or shallow; foramen jugulare posterius completely closed; basisphenoid ventral shape triangular; pectoral scales not extending onto epiplastron; anterior plastral lobe does not reach carapace anterior margin.

DISCUSSION: The ‘‘ Bothremys group’’ (also ‘‘Groupe Bothremys ,’’ ‘‘ Bothremys Leidy, 1865 group’’) of Antunes and Broin (1988), Lapparent de Broin and Werner (1998), Lapparent de Broin and Murelaga (1999), and Lapparent de Broin (2000a) is an informal assemblage consisting of Zolhafah , Rosasia , and Bothremys . However, Lapparent de Broin (2000b) added the term ‘‘pre- Bothremys group’’ for Polysternon plus what we refer to as Foxemys ( Polysternon mechinorum in the usage of Lapparent de Broin, 2000b). In this usage the ‘‘pre- Bothremys group’’ would be the same as our subtribe Foxemydina , and the ‘‘ Bothremys group’’ would be equivalent to our subtribe Bothremydina .

Zolhafah Lapparent de Broin and

Werner, 1998

TYPE AND ONLY INCLUDED SPECIES: Zolhafah bella Lapparent de Broin and Werner, 1998 .

DISTRIBUTION: Late Cretaceous, Egypt.

ETYMOLOGY: zolhafah, Arabic for turtle ( Lapparent de Broin and Werner, 1998).

REVISED DIAGNOSIS: A bothremydid pleurodire of the tribe Bothremydini with the following unique characters among Bothremydini : foramen posterius canalis carotici interni formed by pterygoid, basisphenoid, and quadrate (also occurs in Taphrosphys ); supraoccipital-quadrate contact absent (also absent in Taphrosphyini ); other differentiating characters: dorsal process of premaxilla present, as in Araiochelys and Bothremys , in contrast to Foxemys and Polysternon ; fossa orbitalis not enlarged posteriorly, as in Rosasia , Bothremys , and Chedighaii , but similar to Foxemys ; ridge forming lower orbital rim present, in contrast to Bothremys ; midline depression on ventral surface of premaxilla wide and very shallow; triturating surfaces triangular and very wide, as in Bothremys ; triturating surface pit without complete posterior wall, as in Rosasia , in contrast to completely walled pit seen in Bothremys and Araiochelys ; jugal forms tip and posterior part of pit, as in Rosasia ; lateral edge of maxilla curved but without anterior pinching seen in Foxemys , Rosasia , and Bothremys ; labial ridge relatively thick in contrast to Araiochelys ; fossa pterygoidea absent, as in all other Bothremydini except Foxemys and Polysternon ; incisura columellae auris closed, as in all Bothremydini except Foxemys and Polysternon ; vomer-maxilla contact absent or very small, in contrast to extensive vomer-maxilla contact in Rosasia and Bothremys cooki .

DISCUSSION: See table 10 for a comparison of genera of the tribe Bothremydini .

Zolhafah bella Lapparent de Broin and

Werner, 1998

TYPE SPECIMEN: TUB Vb-173, a nearly complete skull (figs. 115–117).

TYPE LOCALITY: Ammonite Hill, 37 km W of Conoco Channel 20, interdunal channel 31, loc. 271080/1, southwestern Egypt ( Lapparent de Broin and Werner, 1998: 138) (fig. 14).

HORIZON: Dakla Formation, Ammonite Hill Member, Maastrichtian ( Lapparent de Broin and Werner, 1998).

DEPOSITIONAL ENVIRONMENT: Near-shore marine ( Lapparent de Broin and Werner, 1998).

DIAGNOSIS: Same as genus.

ETYMOLOGY: bella, Latin for beautiful ( Lapparent de Broin and Werner, 1998).

REFERRED MATERIAL: None.

PREVIOUS WORK: Zolhafah is described only in Lapparent de Broin and Werner (1998). The six photographs of the skull (pls. I and II) are of good quality. Lapparent de Broin and Werner (1998) identified Zolhafah as a Bothremydidae and member of the ‘‘ Bothremys group’’, an informal taxon containing Zolhafah , Rosasia , and Bothremys , fide Lapparent de Broin and Werner (1998). We include Zolhafah in the tribe Bothremydini , roughly equivalent to the ‘‘ Bothremys group’’.

DISCUSSION: Although we differ with Lapparent de Broin and Werner (1998) in the identification of some parts of the skull of Zolhafah (discussed in the Cranial Morphology section), we agree substantially with their assessment of its relationships.

Rosasia Carrington da Costa, 1940

TYPE AND ONLY INCLUDED SPECIES: Rosasia soutoi Carrington da Costa, 1940 .

DISTRIBUTION: Late Cretaceous, Europe.

ETYMOLOGY: For Prof. Rosas da Silva ( Carrington da Costa, 1940).

REVISED DIAGNOSIS: A bothremydid pleurodire of the tribe Bothremydini with the following unique feature within the Bothremydini : unusually large orbital margin (possibly also in Zolhafah ); other differentiating characters: apertura narium externa oval without prefrontal and premaxillary projections, in contrast to Zolhafah , Bothremys , Araiochelys , and Chedighaii ; dorsal process of maxilla narrow, in contrast to Bothremys ; fossa orbitalis enlarged posteriorly, in contrast to Zolhafah and Foxemys , but as in Bothremys and Chedighaii ; midline depression on ventral surface of premaxilla narrow, as in Bothremys , not wide, as in Zolhafah , Polysternon , Foxemys , and Araiochelys ; triturating surfaces triangular and very wide, as in Zolhafah , Foxemys , and Bothremys ; triturating surface pit present, as in Zolhafah , without complete posterior wall, in contrast to complete pit seen in Bothremys and Araiochelys ; ridge forming lower orbital rim present, in contrast to Bothremys ; jugal forms tip and posterior part of triturating pit, as in Zolhafah ; lateral edge of maxilla curved, in contrast to Araiochelys ; snout pinched, in contrast to Zolhafah ; vomer-maxilla contact extensive, as in Foxemys and Bothremys cooki but in contrast to Zolhafah and other Bothremydini ; fossa pterygoidea shallow, in contrast to deep in Foxemys and Polysternon ; incisura columellae auris closed, as in all Bothremydini except Foxemys and Polysternon ; condylus mandibularis at level of condylus occipitalis, in contrast to Polysternon and Araiochelys ; quadrate-maxilla contact present, in contrast to Foxemys , Polysternon , and Chedighaii , but as in Bothremys and Araiochelys ; foramen posterius canalis carotici interni formed by pterygoid and basisphenoid, in contrast to Chedighaii , Araiochelys , and Bothremys ; carapace rounder than in Cearachelys , with nuchal embayment (see Carrington da Costa, 1958: fig. 1); seven neural bones; costals 7 and 8 meet on midline; plastron with rounded anterior lobe; pectoral scale not reaching entoplastron; gular scale small and restricted to anterior part of epiplastron; pectoral scale reaches mesoplastron; posterior lobe tapering, not parallel-sided.

DISCUSSION: See table 10 for a comparison of genera of the tribe Bothremydini .

Rosasia soutoi Carrington da Costa, 1940

TYPE SPECIMEN: Holotype not designated by Carrington da Costa (1940, 1958), but lectotype designated by Antunes and Broin (1988: 163) as the carapace in plates I and III of Carrington da Costa (1940), uncataloged, Porto, Portugal.

TYPE LOCALITY: Quarry operated as ‘‘Empresa Ceramica do Vouga’’, Quinta do Vilar, Aveiro, Portugal ( Carrington da Costa, 1940) (fig. 14).

HORIZON: ‘‘Une formation gréseuse aturienne, trés probablement du Maestrichtian saumatre’’ ( Carrington da Costa, 1940: 17). Late Campanian to Maastrichtian ( Antunes and Broin, 1988).

DEPOSITIONAL ENVIRONMENT: ‘‘Tropical to subtropical climate in an area constituted by a low coastal plain only occasionally linked to the sea, saturated with fresh water’’ ( Antunes and Broin, 1988).

DIAGNOSIS: Same as genus.

ETYMOLOGY: For Dr. Alberto Souto ( Carrington da Costa, 1940).

REFERRED MATERIAL: Uncataloged skull (figs. 120, 121) in the Universidade Nova de Lisboa, Portugal, described and figured in Antunes and Broin (1988: figs. 3–8, pl. 3, fig. 3, pl. 4, fig. 3, pl. 5, figs. 1–4), associated with a peripheral bone; three femoral fragments; four cervical vertebrae ( Antunes and Broin, 1988); shells in this same collection are: MTA 1 ( Antunes and Broin, 1988: pl. 3, figs. 1, 2), MTA 2 ( Antunes and Broin, 1988: pl. 4, figs. 1, 2, pl. 1, fig. 1); two shells (only one figured) in the Serviços Geológicos de Portugal de Lisbonne ( Carrington da Costa, 1958: pls. 3, 4); one shell in the Faculdade de Ciências e Tecnologia, Universidade de Coimbra ( Carrington da Costa, 1958: pls. 5, 6).

PREVIOUS WORK: Sauvage (1898) seems to have been the first to describe a specimen of what Carrington da Costa (1940) named Rosasia soutoi . Sauvage based his taxon on a carapace, and later ( Carrington da Costa, 1958) described more complete shells. Antunes and Broin (1988) described a skull identified as this taxon, although only a shell fragment was associated with the skull. The association is supported by the fact that the shells and the skulls all belong to the same group and were found in the same area and horizon, in the absence of other pleurodires.

DISCUSSION: Lapparent de Broin and Werner (1998) rejected the Antunes and Broin (1988) identification of some cervicals as belonging to Rosasia and identified them as varanoid instead. We have seen these cervicals and agree that they are very different from the few other known bothremydid cervicals, but strange things happen, and we do not think they are lizard vertebrae. In any case, these cervicals are not included in our dataset.

Araiochelys , new genus

TYPE AND ONLY INCLUDED SPECIES: Araiochelys hirayamai , n. sp.

DISTRIBUTION: Paleocene of Morocco.

ETYMOLOGY: Araios, Greek for narrow, in allusion to narrow triturating surfaces; chelys, Greek for turtle.

DIAGNOSIS: A bothremydid pleurodire of the tribe Bothremydini with the following unique features within Bothremydini : preorbital part of skull narrower than in all other Bothremydini ; triturating surfaces narrower than in all other Bothremydini ; and apertura narium externa facing anterolaterally in contrast to anteriorly; other differentiating characters: dorsal process of maxilla (orbitonarial bar) narrow in contrast to Bothremys ; fossa orbitalis enlarged posteriorly as in Bothremys , Rosasia , and Chedighaii and in contrast to Foxemys and Zolhafah ; ridge forming lower rim of orbit relatively distinct in contrast to Bothremys ; midline depression on ventral surface of premaxilla narrow, as in Rosasia and Bothremys , not wide, as in Zolhafah , Polysternon and Foxemys ; triturating surface pit present and completely developed, as in Bothremys , not partial, as in Zolhafah and Rosasia ; jugal forms tip and posterior part of pit; lateral edge of maxilla relatively straight, in contrast to Bothremys , Rosasia , and Zolhafah ; anterior part of vomer short, with narrow maxilla contact, in contrast to broad contact in Bothremys cooki , Rosasia , and Foxemys ; fossa pterygoidea absent; incisura columellae auris closed, as in all Bothremydini except Foxemys and Polysternon ; condylus mandibularis anterior to level of condylus occipitalis but not far anterior, as in Polysternon ; quadrate-maxilla contact present in contrast to Foxemys , Polysternon , and Chedighaii , but as in Bothremys and Rosasia ; foramen posterius canalis carotici interni formed by pterygoid and quadrate, in contrast to Rosasia , Zolhafah , Polysternon , and Foxemys ; lower jaw with triturating pits and long processus retroarticularis; carapace with discontinuous neural series; narrow vertebral scutes, very long second vertebral; plastron with narrow posterior lobe and wide bridge; posterior lobe with parallel lateral margins; mesoplastron wider than long; pointed xiphiplastral ends with wide anal notch; humeropectoral sulcus posterior to the epihyoplastral suture, crossing entoplastron; pectoroabdominal sulcus anterior to the mesoplastron.

DISCUSSION: Araiochelys is a member of the Bothremydini , on the basis of skull features. The shell characters of this taxon differ from those of the tribe Taphrosphyini (which also occur in this unit) as follows: (1) finer ornamentation on the shell surface; (2) xiphiplastron much longer than wide; and (3) ischiac scar triangular and more anteriorly placed, not as close to the posterior margin of the plastron, as in Taphrosphys .

See table 10 for a comparison of genera of the tribe Bothremydini .

Araiochelys hirayamai , new species

TYPE SPECIMEN: THUg 3338, skull (figs. 124, 125), lower jaws (figs. 237, 238), partial disarticulated shell (figs. 262, 263), including a few carapace fragments (left first and fifth costals, left third, seventh, and eighth peripherals and other fragments), nearly complete plastron, and limb bones.

TYPE LOCALITY: Ouled Abdoun phosphate basin, Morocco (figs. 14–16). The Ouled Abdoun Basin is about 100 km southeast of Casablanca, Morocco. The basin, extending some 100 km from east to west and 80 km from north to south, is the largest phosphate basin in Morocco. The stratigraphy of the phosphates in this region (fig. 17) has been developed by Arambourg (1935, 1952), primarily on the basis of the selachians. The fossiliferous deposits range in age from the Maastrichtian to the Ypresian ( Arambourg, 1952; Noubhani and Cappetta, 1997).

Vertebrate remains from the phosphates of Morocco are abundant. Surprisingly, there are no turtles reported in the phosphates of Morocco by Arambourg (1952). The first turtle remains from the Moroccan phosphates were reported by Ambroggi and Arambourg (1951) from the Maastrichtian of Oued Erguita, some 200 km southwest of the Ouled Abdoun Basin. They indicated abundant turtle remains as ‘‘chelonian indet.’’ ( Ambroggi and Arambourg, 1951). More than 20 years later, Moody (1976) reported a large ‘‘pelomedusid turtle’’ shell from the Paleocene of Benguerir in the Cantour Basin. Gmira (1995) mentioned a large skull of a cheloniid sea turtle from the presumed Maastrichtian of Benguerir. More extensive turtle remains have been reported from the Ouled Abdoun Basin only recently ( Karl et al., 1998; Lapparent de Broin, 2000a; Gaffney and Tong, 2003; Hirayama and Tong, 2003; Tong and Hirayama, 2002, 2004).

The turtle remains from the Ouled Abdoun Basin are very abundant and diversified. Most specimens were collected by local people for commercial purposes ( Osborne, 2000); their exact location and stratigraphic level are therefore often unknown. However, some specimens have been collected in situ during fieldwork for the present project, and some have the original locality information obtained from the local collectors. The specimens from the Maastrichtian deposits are easily distinguished from those from the Paleogene since they are contained in soft yellow phosphates, which are different from the overlying gray-white Tertiary sediments. The turtle remains are further dated, when possible, by the shark teeth included in the original matrix around the specimen.

The phosphate deposits of the Ouled Abdoun Basin contain both articulated skeletons and isolated elements. The fact that most specimens are skulls is due to selective collecting by the local people. The abundance of the fossils collected also depends a great deal on the extent and position of phosphate exploration. The Danian beds have yielded the most abundant and diverse turtles, partly because the upper part of the Danian is a hard limestone layer that is not removed by the miners. The free surface left behind by the excavating machines makes the collection of fossils easier. The reptile remains from the Maastrichtian layers were rather fragmentary; the abundant and more complete specimens from these beds have been reported only recently, since this layer was rarely excavated in the past.

DEPOSITIONAL ENVIRONMENT: Near-shore marine. The phosphate deposits of the Ouled Abdoun Basin, as well as the other phosphate basins of Morocco, were formed in long, narrow gulfs opening to the Atlantic margin in a tropical climate ( Arambourg, 1952; Lucas and Prévot-Lucas, 1996). A bathymetric study ( Arambourg, 1952) based on the fish fauna of Maghreb indicated deposition in a near-shore marine basin of shallow water during both the Maastrichtian and Eocene. The Maastrichtian deposits, however, have been formed in deeper water than those of the Eocene ( Arambourg, 1952). The presence of some selachians, such as Alopias , Heptranchias , Hexanchus , and Echinorhinus in the Ypresian deposits, indicates a bathyal influence, which might indicate deeper water than previously thought. The upwelling currents, which are responsible for the phosphatogenesis, are probably related to the presence of these bathyal forms in the Ouled Abdoun Basin, which was situated more than 100 km from the opening of the gulf during that period ( Cappetta, 1981).

The vertebrate assemblage from the Ouled Abdoun Basin consists mostly of marine species. All turtle remains from that basin (table 11) are marine, which include cheloniids ( Karl et al., 1998; Tong and Hirayama, 2002; Hirayama and Tong, 2003), dermochelyids ( Tong and Hirayama, 2004), and bothremydid side-necked turtles ( Gaffney and Tong, 2003). A very specialized trionychoid turtle ( AMNH 30001, 30558, 30001) with broad secondary palate and pits similar to those in Bothremys was presumably also marine. Besides turtles, selachians ( Arambourg, 1935, 1952; Cappetta, 1981, 1983, 1984, 1986, 1988; Noubhani and Cappetta, 1992, 1994, 1997), bony fishes ( Cavin et al., 2000), and crocodiles ( Arambourg, 1952; Buffetaut and Wouters, 1979) were reported from both Maastrichtian and Tertiary beds. In addition, the Maastrichtian beds have yielded mosasaurs and plesiosaurs ( Arambourg, 1952; Bardet et al., 2001), dinosaurs ( Pereda Suberbiola et al., 2004; Buffetaut et al., 2005), and pterosaurs ( Pereda Suberbiola et al., 2003). The nonmarine taxa, assumed to be floated bodies, include a few dinosaurs from the Maastrichtian and mammals from the Tertiary beds ( Gheerbrant et al., 1996, 1998, 2001, 2002, 2003).

HORIZON: Danian, Paleocene, based on shark teeth in matrix (Cappetta, personal commun.) (fig. 17, table 11).

DIAGNOSIS: Same as genus.

ETYMOLOGY: In recognition of the work on turtles by Dr. Ren Hirayama, Waseda University. His lifelong contributions to turtle systematics and his consistent support of this project are gratefully recognized.

REFERRED MATERIAL: MDEt 25, an incomplete and disarticulated shell, collected by H. Tong, L. Cavin, and S. Xerri during January 1999; Danian, Early Paleocene, collected on the surface of Dalle Couche 2 (Danian, Paleocene), Recette 4, Ouled Abdoun Basin, Morocco, consists of neurals 1– 2, left costals 1–4 (the fourth is incomplete), right costals 2–5 (costals 3 and 5 are incomplete), left 10th and 11th peripherals, one peripheral of bridge region, right hypoplastron and xiphiplastron, and other fragments.

MDEt 25 is identified as Araiochelys hirayamai because of the similar size, the shape and structure of the first and fifth costal plates, the similar development of the axillary and inguinal buttress scars, the shape of the posterior lobe of the plastron, and the shape and position of the pubic and ischiac scars. In the context of the known fauna, this identification is likely, but the diversity of bothremydids in the fauna must be kept in mind when considering this identification. The carapace length of MDEt 25 is estimated at 300 mm. Both MDEt 25 and THUg 3338 are from the Danian beds of the Ouled Abdoun Basin, Morocco. None of the plastron and only part of the carapace restoration (fig. 263) are dependent on the identification of MDEt 25 as Araiochelys .

PREVIOUS WORK: None.

DISCUSSION: Araiochelys is unique among the tribe Bothremydini in having a relatively narrow skull, narrow triturating surfaces, and narrow lower jaw. If its distinctions from the other tribe Bothremydini are interpreted as minor, the question can be asked: Is Araiochelys a narrow-jawed morph of anoth- er already-recognized species? It is found in the same locality and units as Bothremys maghrebiana , and it makes sense to examine the possibility that Araiochelys hirayamai and Bothremys maghrebiana might be the same species.

The existence of five skulls identified as B. maghrebiana provides at least some chance of assessing the range of variation in that

TABLE 11

Moroccan Phosphate Specimens with Original Data andłor Dated by Shark Teeth

Specimens are named and described in this paper unless another reference is given.

Ypresian

Phosphatochelys tedfordi MDEt 26, skull AMNH 30008, skull, Gaffney and Tong, 2003

Bothremys kellyi AMNH 30553, skull

Bothremydini indet. AMNH 29989, lower jaw, Ouled Abdoun basin, couche 1, specimen purchased with original information from the collector or dealer.

Ummulisani rutgersensis AMNH 30569, skull

Thanetian

Tasbacka ouledabdounensis AMNH 30033, skull, recette 4, Tong and Hirayama, 2002, specimen purchased with original information from the collector or dealer. AMNH 30032, skull

Danian

Pitted cryptodire, undescribed AMNH 30001, skull, in prep. AMNH 30558, skull & lower jaw AMNH 30554, skull

Osteopygis emarginatus MDEt 27, skull, Hirayama and Tong, 2003 MDEt 28, lower jaw, recette 4, Dalle couche 2, specimen purchased with original information from the collector or dealer. MDE 29, lower jaw ‘‘ Osteopygoides ’’ type, skull, Karl et al., 1998 ‘‘Osteopygoides’’, skull MDEt 34, hyoplastron, recette 4, Dalle couche 2, specimen collected during the fieldwork in January 1999.

Labrostochelys galkini AMNH 29984, skull

Bothremys maghrebiana AMNH 30234, skull AMNH 30561, skull, recette 4, Dalle couche 2, specimen purchased with original information from the collector or dealer. AMNH 30041, skull, recette 4, Dalle couche 2, specimen purchased with original information from the collector or dealer. MHNL 20-268370, skull

Taphrosphyini indet. AMNH 30559, post. part of plastron + humerus

Taphrosphys ippolittoi AMNH 30500, including skull AMNH 30042, skull

Araiochelys hirayamai THUg 3338, skull + shell MDEt 25, partial shell, recette 4, Dalle couche 2, specimen collected during the fieldwork in January 1999.

Maastrichtian

Dermochelyid indet. MDEt 06, hyoplastron, couche 3, Tong and Hirayama, 2004

Chelonioidea indet. MDEt 39, lower jaw, couche 3, specimen purchased with original information from the collector or dealer. MDEt 40, 2 peripherals, Oued Zem, couche 3, specimen collected during the fieldwork in January 1999.

species. Some characters can be measured (appendix 5), and others are judged by observation, which is not necessarily less objective. Nonetheless, the available material is insufficient for a well-founded answer to this question, and this analysis must be considered in that context. Although all six skulls have postmortem damage, none seems to be conspicuously distorted by dorsoventral or mediolateral crushing.

Modern studies of infraspecific variation of living turtles show that a few trionychid ( Dalrymple, 1977) and emydid ( Lindeman, 2000) species do develop broad-jawed and narrow-jawed morphs. Chelids are known to have broad-jawed morphs ( Cann, 1998), but these have not been studied in detail. These recent species with variations in the size of the triturating surfaces are usually interpreted as size-related, with large, older females developing the widest surfaces, although this is not consistent in all reported taxa. While the six skulls examined here do vary in size, the single Araiochelys skull is only slightly larger than the smallest B. maghrebiana skull ( AMNH 30041). The Araiochelys skull is about the same size as two of the B. maghrebiana skulls ( AMNH 30522, AMNH 30561), and it is about 20 % smaller than the two largest B. maghrebiana skulls. This comparison shows that the single Araiochelys skull falls at the small end of the size range among these specimens. For the ratios detailed below, see figure 315 and appendix 5 for measurements.

1. Skull width: The skull of Araiochelys is longer than wide and is narrower than any of the B. maghrebiana skulls. The width/length (B/A) ratio of Araiochelys is 0.96. All of the B. maghrebiana skulls are wider than long; the width/length ratio of B. maghrebiana varies from 1.04 to 1.16. It is hard to judge the significance of this difference with such a small sample, but the senior author’s measurements of recent Podocnemis suggest that such variation is common within a population.

2. Preorbital skull width: By observation, it is apparent that the snout of Araiochelys is narrower than those in the five B. maghrebiana skulls. Skull width at midorbit (H) gives a ratio relative to the basicranial length (H/A) of 0.67 for Araiochelys and a range of 0.77– 1.0 for the B. maghrebiana skulls. Comparing this width with available trionychids and

3.

4.

5.

6.

7. emydids suggests that these differences are well within the range of narrow- and broad-jawed morphs seen in these species.

Width of triturating surfaces: This measurement (M/A) gives ratios of 0.20 for Araiochelys and a range of 0.26–0.35 for B. maghrebiana . An unusually wide triturating area is a nearly universal characteristic of the Bothremydini , except for Araiochelys . The phylogenetic analysis is based on many characters, but the MPC still puts Araiochelys as sister taxon to Bothremys + Chedighaii , even when maxilla width and related characters are excluded. In chelids, trionychids, and emydids, most of the taxa within each family are predominantly narrow-jawed, with the broad-jawed forms being variations from the norm. Araiochelys would oppose this pattern, with a narrow-jawed variant from the wide-jawed norm. Nonetheless, it would still be possible to interpret Araiochelys as a young, narrow-jawed male, and Bothremys maghrebiana as the older females.

Depth of maxilla (labial ridge) below orbit: The maxilla in Araiochelys is shallower than those in B. maghrebiana . However, the range of variation (labial ridge depth/basicranial length A) within B. maghrebiana , 0.20–0.27, includes an extreme that is close to the ratio for Araiochelys , which is 0.18.

Thickness of orbitonarial bar: This character does not seem to be related to the width of the triturating surface. It is the distance between the aperture narium externa and the orbit (orbitonarial bar/basicranial length A). In Araiochelys , the ratio is 0.11, and in B. maghrebiana , the range is 0.15–0.17. This seems to be a consistent character differentiating these possible taxa.

Apertura narium externa faces more anterolaterally, and orbits face more laterally: These characters may be related to the large triturating surfaces in that they reflect the angle of the skull surface to the horizontal plane. However, when looking at chelids, emydids, and trionychids, there are no significant differences in the orientation of these openings between broad- and narrow-jawed morphs.

Dorsal maxillary process reaches onto skull roof: This character is the position and shape of the prefrontal-maxilla suture. In Bothremys , the suture is more dorsomedial and trends anteromedially, in contrast to the straight suture of Araiochelys . However, the suture is clear in only two B. maghrebiana specimens, and in one of these it is not bilaterally symmetrical, making it a weak distinguishing feature.

8. Ventral rim of orbit forming distinct ridge: None of the B. maghrebiana skulls has a well-defined ridge marking the lower orbital margin, as seen in Araiochelys . This does not seem to be related to the triturating surface size.

9. Structure of triturating surface pit: The triturating surface is formed differently in the two taxa. The triturating pit in Bothremys maghrebiana has the jugal forming its tip, and the maxilla and palatine broadly meeting posterior to the pit. In Araiochelys the jugal extends posteriorly to separate the maxilla and palatine.

Araiochelys does not fall within the range of morphologic or size variation shown by B. maghrebiana , but it is not very far from the extremes of that variation in some characters. The significance of this is hard to judge. A mathematical analysis more sophisticated than a simple ratio could be performed on these measurements, but it would be unlikely to produce definitive conclusions given the very small sample sizes. Araiochelys could still be interpreted as a narrow-jawed morph and synonymized with B. maghrebiana , but the other characters are inconsistent with this interpretation. The phylogenetic analysis shows that Araiochelys consistently falls outside the monophyletic group Bothremys + Chedighaii , even when the maxilla width and associated characters are deleted. Examining the MPC shows that no matter where Araiochelys is placed within the Bothremydini , its narrow skull and jaws are a homoplasy. If THUg 3338 were a variant of one of the Bothremys species, it would be expected to fall within Bothremys or at least within the Bothremys + Chedighaii clade, based on the other characters. Given the limits of the available material, it is not possible to completely exclude the interpretation that THUg 3338 should be included in B. maghrebiana , but at present, the evidence is much more in favor of recognizing it as a separate taxon outside Bothremys + Chedighaii .

Bothremys Leidy, 1865

Karkaemys Zalmout, Mustafa, and Wilson, 2005 .

TYPE SPECIES: Bothremys cooki Leidy,

1865.

INCLUDED SPECIES: B. cooki , B. maghrebiana , B. kellyi , and B. arabicus .

DISTRIBUTION: Presumed Late Cretaceous of the eastern United States, Late Cretaceous of Middle East, and Paleocene to Early Eocene of Morocco.

ETYMOLOGY: Bothros, Greek for pit, and emys, Latin for turtle.

REVISED DIAGNOSIS: A bothremydid pleurodire of the tribe Bothremydini with the following unique features: dorsal process of maxilla broad, separating apertura narium externa and orbital rim more than in any other Bothremydini ; differs from Chedighaii in having well-developed maxilla-jugal pits on triturating surface; suborbital depth of maxilla deeper than in other Bothremydini except Chedighaii hutchisoni ; orbits face strongly upward, in contrast to all other Bothremydini except Chedighaii ; basisphenoid-quadrate contact very narrow, in contrast to all other Bothremydini except Chedighaii ; lower jaw with deep pit on triturating surface.

DISCUSSION: Zug (2001) identified a series of shell elements and a humerus from the Pliocene Lee Creek Mine of North Carolina as Bothremys , species unspecified. The external surface texture of the shell elements is generally smooth or randomly rugose, agreeing with Chedighaii barberi and many Pelomedusoides. The humerus is unknown in most taxa, but diagnostic differences, if any, between bothremydids and podocnemidids are not apparent. The nuchal bone, USNM 186773 (Zug, 2001: fig. 2A, B), is not emarginate, as in Chedighaii (formerly Bothremys barberi ), so there is evidence that the Lee Creek pelomedusoid is not Chedighaii . The Lee Creek nuchal could be from a bothremydid or podocnemidid; its morphology is consistent with the extinct Bairdemys and Shweboemys group podocnemidids. The Lee Creek Pliocene ‘‘ Bothremys ’’ is incertae sedis at the level of Pelomedusoides.

Hutchison and Weems (1998) identified fragmentary shell elements as? Bothremys (and Taphrosphys ; see this genus for discussion below) from the Paleocene Williamsburg Formation of South Carolina. The specimens are not represented by complete entoplastra, xiphiplastra, or nuchals, which would be diagnostic for Taphrosphys , but they are clearly Pelomedusoides. The absence of a shell for the redefined Bothremys as used here would make shell identifications difficult in any case. The? Bothremys fragments show a smooth surface texture very similar to what was called Bothremys barberi in the past and what is here referred to the genus Chedighaii . Unfortunately, the smooth surface texture is common in Pelomedusoides and does not even allow differentiation of Bothremydidae from Podocnemididae . Thus, this material is incertae sedis at the level of Pelomedusoides. Nonetheless, it is interesting to note the occurrence of two distinct pelomedusoid species, at least one of which is a bothremydid, in the same Late Paleocene unit of the Atlantic Coastal Plain.

Garcia and Reynoso (2002) reported ‘‘ Bothremys ’’ from both shells and skulls from the Campanian of Coahuila State, Mexico. We have been unable to see these specimens and cannot definitively comment on the identifications, but thanks to Don Brinkman and Rubén Armando Rodriguez de la Rosa, we have been able to examine photographs of some of this material. The shells are Pelomedusoides and are consistent with a bothremydid like Chedighaii . The skull specimens look bothremydid and also seem to be similar to Chedighaii , but sutures, presence/absence of pits, and other diagnostic features are not clear in the photographs. For the present, we cannot substantiate the identification, but it is a likely bothremydid.

See table 10 for a comparison of genera of the tribe Bothremydini .

Bothremys cooki Leidy, 1865

TYPE SPECIMEN: AMNH 2521, skull and jaws (figs. 129, 130, 239, 279). Originally Rutgers University 1.KV-6 141, 142.

TYPE LOCALITY: ‘‘The Green-sand near Barnsboro, Gloucester County, New Jersey’’ ( Leidy, 1865: 110) (fig. 18).

HORIZON: At this locality, the most likely source of the specimen is the Maastrichtian Navesink Formation (thanks to Neil Landman for helping with this assessment).

DEPOSITIONAL ENVIRONMENT: Near-shore marine; see Gallagher (1993) for discussion of the New Jersey sequence.

DIAGNOSIS: A member of the genus Bothremys with the following unique features: triturating pit formed entirely by widely exposed jugal; small jugal exposure in orbital rim; elongate vomer with wide maxilla contact; midline concavity formed by premaxilla and vomer elongate and narrow; apertura narium interna opens more posteriorly than in other species. Other distinguishing features: ventral rim of orbit without distinct margin, in contrast to B. kellyi and B. arabicus ; postorbital-palatine not in contact in posterior surface of septum orbitotemporale, in contrast to B. maghrebiana ; jugal prevents maxilla-palatine contact posterior to pit, in contrast to B. maghrebiana ; lower jaws wider than in B. maghrebiana .

ETYMOLOGY: ‘‘The species is dedicated to Prof. George H. Cook, of Rutger’s College, New Brunswick, New Jersey, by whom the specimen was obtained, and through whose explorations our knowledge of the vertebrate fauna of the Green-sand formations of New Jersey has been greatly enriched’’ ( Leidy, 1865: 113). See Sidar (1976) for a biography of Cook, who also collected specimens of Taphrosphys sulcatus .

REFERRED MATERIAL: AMNH 29444, right otic chamber (figs. 131, 132, 135), Elizabethtown, North Carolina, Campanian, Black Creek Formation (see Baird and Horner, 1979, for map and discussion of the Black Creek Formation), collected by R. Jerry Britt, Jr., 1983–1984.

PREVIOUS WORK: In 1865, Joseph Leidy recognized Bothremys as a pleurodire and compared it with Podocnemis : ‘‘Of all recent turtles with which I am acquainted, the fossil skull, in general physiognomy and structure, resembles most that of the great turtle of the Amazon, Podocnemis expansa . From this, and all others, however, it differs in several striking peculiarities’’ ( Leidy, 1865: 110). Leidy went on to describe and figure (pl. 18, figs. 4–7, reproduced here as fig. 19) the skull and jaws. Leidy’s identification of his new skull as a form related to Podocnemis was quite astute for the time. Pleurodires were poorly represented in collections and their diagnostic characters were not easily determinable from the literature. As in many of his other discoveries, Leidy’s work stands the test of time.

George Baur examined the skull of Bothremys and , in 1891, erected the family Bothremydidae for Bothremys and Taphrosphys and included the family in the Pleurodira . Oliver Perry Hay (1908) also examined the skull and redescribed and figured (pl. 23, figs. 2, 3, figs. 96, 97) it, also using the family Bothremydidae . Gaffney and Zangerl (1968) published the most extensive and completely illustrated (figs. 13–16, 19A, B, 20, 21C, D, 22A–C) redescription of Bothremys cooki to date. They followed the then-current inclusion of bothremydids in the family Pelomedusidae . Gaffney and Zangerl (1968) includ- ed the species ‘‘ Podocnemis ’’ barberi Schmidt in Bothremys on the basis of the pitted lower jaws and the enclosed stapedial canal. This species is placed in the genus Chedighaii (q.v.) here. Many identifications of Bothremys in the literature (e.g., Robb, 1989) are based on ‘‘ Bothremys ’’ (5 Chedighaii ) barberi and no longer represent age and geographic distributions of Bothremys as here conceived.

DISCUSSION: As Bothremys cooki is now based primarily on the type skull from Barnsboro, New Jersey, its age is of some interest. The region around Barnsboro includes the Danian Hornerstown Formation, as well as the late Maastrichtian Navesink Formation. However, the West Jersey Marl Company had pits just south of Barnsboro that were almost entirely in the Cretaceous, and they have yielded a series of dinosaur and other fossils ( Gallagher, 1993). Close examination of the type skull of Bothremys cooki, AMNH 2521 , has shown glauconite grains and glauconitic clay remaining as matrix, consistent with either Hornerstown or Navesink Formations. However, the bone of the specimen is dark brown, not the greenish-gray of typical Hornerstown bone. Furthermore, Gallagher (1993) suggested that the bone-producing horizon at Barnsboro was in the Navesink. At present, it seems likely that the type of Bothremys cooki is Maastrichtian rather than Paleocene.

The identification of a right otic chamber, AMNH 29444, as Bothremys cooki is based on the very limited overlap area of the basisphenoid, the agreement in size ( B. cooki is significantly smaller than all known specimens of Chedighaii ), and the close agreement with B. maghrebiana . These are not overwhelmingly compelling reasons, and the otic chamber has been added to the restoration only as an additional side view (fig. 127D). Although described in the skull morphology section under Bothremys cooki , it is quite possible that this specimen is not Bothremys cooki , and information from it has not been used in the dataset.

See table 12 for a comparison of the species in Bothremys .

Bothremys maghrebiana , new species

TYPE SPECIMEN: AMNH 30561, nearly complete skull (figs. 142, 143, 145), field number A8 of H. Tong.

TYPE LOCALITY: Recette 4, Ouled Abdoun Basin, Morocco (figs. 14–16).

HORIZON: Dalle Couche 2, Danian, Early Paleocene (fig. 17, table 11). Information about the stratigraphic level and age of the locality of this specimen are from the Moroccan collector via H. Tong.

DEPOSITIONAL ENVIRONMENT: Near-shore marine; discussion of Moroccan phosphates is under Araiochelys hirayamai .

DIAGNOSIS: A member of the genus Bothremys with the following unique features: postorbital-palatine contact on posterior surface of septum orbitotemporale (unknown in B. kellyi and B. arabicus ); jugal exposed only in tip of triturating pit, allowing broad contact of palatine and maxilla; midline concavity formed by premaxilla and maxilla short and narrow; other distinguishing features: very narrow vomer-maxilla contact, in contrast to B. cooki ; ventral rim of orbit without distinct margin, in contrast to B. kellyi and B. arabicus ; lower jaws narrower than in B. cooki .

ETYMOLOGY: From ‘‘Maghreb’’, Arabian name for the three countries ( Tunisia, Algeria, and Morocco) in northwest Africa.

REFERRED MATERIAL: AMNH 30234, skull (figs. 140, 141), Danian phosphates based on shark teeth in matrix (Cappetta, personal commun.), Oued Zem, Ouled Abdoun Basin, from F. Escuillie´; AMNH 30041, skull (figs. 138, 139, 278B), Ouled Abdoun Basin, Danian phosphates based on shark teeth in matrix (Cappetta, personal commun.), from B. Segaoui; AMNH 30522, skull (fig. 144) and jaws (figs. 240, 241), Paleogene, Ouled Abdoun phosphates, Morocco, based on matrix; MHNL 20-268370, skull, Danian phosphates, Ouled Abdoun Basin, Morocco.

PREVIOUS WORK: None.

DISCUSSION: The discovery of a series of well-preserved skulls in the Moroccan phosphates has significantly improved knowledge of variation in the cranial morphology in the genus Bothremys . The Moroccan skulls are similar to Bothremys cooki in shape and size, although the American species seems to be Late Cretaceous and the African species Paleocene in age.

See table 12 for a comparison of the species in Bothremys .

Bothremys kellyi , new species

TYPE SPECIMEN: AMNH 30553 (figs. 148, 149, 285), a nearly complete skull, from F. Escuillie´.

TYPE LOCALITY: Ouled Abdoun Basin, Morocco (figs. 14–16).

HORIZON: Early Ypresian, Early Eocene, Phosphates (Cappetta, personal commun., from shark teeth) (fig. 17).

DEPOSITIONAL ENVIRONMENT: Near-shore marine; discussion of Moroccan phosphates is under Araiochelys hirayamai .

DIAGNOSIS: A member of the genus Bothremys with the following unique features: dorsal process of premaxilla contacts prefrontals to separate apertura narium externa; sulcus eustachii constricted into narrow channel formed by squamosal and

TABLE 12

Species of Bothremys quadrate; anterior margin of otic chamber swollen into overhanging ridge; large ridge on dorsal surface of squamosal and opisthotic; basisphenoid as well as pterygoid and quadrate forming foramen posterius canalis carotici interni.

ETYMOLOGY: For Jeanne Kelly, in recognition of her skill and efforts in preparing turtle skulls and her years of service to the Department of Paleontology, American Museum of Natural History.

REFERRED MATERIAL: None.

PREVIOUS WORK: None.

DISCUSSION: This Eocene Bothremys is larger than B. cooki and B. maghrebiana , and nearly the size of B. arabicus . The unique ear morphology, with a very deep channel for the eustachian tube (fig. 285), is unique among turtles and is a good autapomorphy for this species.

See table 12 for a comparison of the species in Bothremys .

Bothremys arabicus ( Zalmout, Mustafa, and