Novocrania anomala ( Müller, 1776 )

Jeffrey H Robinson, 2017, A review of all Recent species in the genus Novocrania (Craniata, Brachiopoda), Zootaxa 4329 (6), pp. 501-559 : 507-513

Novocrania anomala ( Müller, 1776)

Stratigraphic range: Recent

1776: Patella anomala Müller, Zoologiae Danicae, p. 237.

1788: Patella anomala Müller, Zoologia Danica, vol. 1, p. 4, pl. 5, figs 1–8.

1798: Orbicula anomala (Müller), Cuvier, Tableau élément. l’hist. natur. des Anim, p. 435, 436. 1801: Crania personata Lamarck, Systeme des Animaux sans Ƒertebres, p. 138. 1815: Patella distorta Montagu, Trans. of the Linn. Soc., 11, p. 195, pl. 13, fig. 5. 1817: Orbicula anomala (Müller), Cuvier, Le Régne Animal dist. d’aprés son org., p. 504. 1819: Crania personata Lamarck, Hist. nat. des Anim. sans vert, p. 243–245.

1822: Crania personata Lamarck, Sowerby, Trans. of the Linn. Soc., p. 471, fig. 3a –e. 1822: Criopus anomalus Fleming, The Philosophy of Zoology, vol. 2, p. 499.

1846: Crania anomala (Müller), Lovén, In. Moll. litora Scand. Occident. habit., p. 29. 1852: Criopus orcadensis Leach, Molluscorum Britanniae Synopsis, p. 358.

1871: Crania anomala (Müller), Dall, Bull. Harv. Mus. Comp. Zoo., p. 32.

1986: Neocrania anomala (Müller), Lee & Brunton, Bull. Nat. Hist. Mus. (Geo.), 40 (4), p. 152. 2001: Novocrania anomala (Müller), Lee & Brunton, Bull. Nat. Hist. Mus. (Geo.), 57 (1), p. 5.

1871: Crania (? anomala var.) pourtalesii Dall, Bull. Mus. Comp. Zoo., 3(1), p. 35, pl. 1, fig. 7a –b. 1886: Crania pourtalesii Dall, Dall, Bull. Mus. Comp. Zoo., 12, p. 205.

1920: Crania pourtalesii Dall, Dall, Proc. of the United States Nat. Mus., 57, p. 273. 1954: Crania pourtalesii Dall, Cooper, Fish. Bull. Fish. Wild. Serv., 55, p. 363, 364. 1971: Crania pourtalesii Dall, Jackson et al., Science, 173, p. 624.

1977: Crania pourtalesi Dall, Cooper, Stud. Trop. Ocean., p. 53, pl. 2, fig. 5–11.

1977: Crania aff. C. pourtalesi Dall, Cooper, Stud. Trop. Ocean., p. 54, pl. 28, fig. 18. 1986: Neocrania pourtalesi (Dall), Lee & Brunton, Bull. Nat. Hist. Mus (Geo.), 40 (4), p. 152. 1990: Neocrania pourtalesi (Dall), Zezina, Akad. Nauk SSSR, Okean. Instit., 126, p. 131. 1992: Crania pourtelesi Dall, Emig, Lethaia, 25, p. 297.

2001: Novocrania pourtalesi (Dall), Lee & Brunton, Bull. Nat. Hist. Mus. (Geo.), 57 (1), p. 5.

Synonymy. The early taxonomy of the family Craniidae is very confused as the early taxonomists struggled with the differences between limpet molluscs, discinid brachiopods and craniid brachiopods. A great many synonymous names were proposed, including many for N. anomala and N. turbinata . Dall (1871) reviewed the family Cranidae and resolved much of the confusion. Dall (1871) listed extensive synonymies for the Family Craniidae , the genus Crania Retzius, 1871 , and three species. The list of synonymous names under Crania anomala included 5 genera and 9 species by 29 authors (Dall listed a separate synonymy for Crania turbinata ). Not all of the early synonyms are discussed or listed herein.

Müller (1776) briefly described this species as Patella anomala , but did not mention the ventral valve. Müller (1788) included more detailed descriptions and illustrations of both valves, the lophophore, the muscle scars, ventral mantle canals and specimens attached to a rock. Cuvier (1798; 1817) described specimens as Orbicula anomala . The genus Orbicula became associated with discinids then fell out of usage (Lee & Brunton 1986).

Fleming (1822) synonymized Patella anomala and Patella distorta under the name Criopus anomalus . Leach (1852) described, but did not figure, specimens he named Criopus orcadensis from the Orkney Islands that are probably N. anomala . Poli (1791; 1795) introduced the genera names Criopus and Criopoderma for the soft parts and hard parts respectively of several brachiopods, thus a single animal might have two genus names. Lee & Brunton (1986, p. 150) noted that “In modern taxonomy this is clearly unacceptable” and applied for suppression of Criopus and Criopoderma .

Sowerby (1822) described and figured dried specimens attached to a rock from the Shetland Islands and synonymised Patella distorta under Crania personata . Lovén (1846) synonymized Patella distorta and Crania personata under Crania anomala . Dall (1871) published his extensive synonymy of C. anomala . Lee and Brunton (1986) proposed a new genus Neocrania with N. anomala as its type species. In 2001, Lee & Brunton proposed the replacement genus name Novocrania as the name Neocrania was preoccupied.

Dall (1871) first described and illustrated the species Crania (? anomala var.) pourtalesii from a few specimens dredged up in the Caribbean and stated that these specimens might represent a variety of Crania anomala , but if a larger number of specimens proved it to be distinct he proposed the species name pourtalesii after the collector, Mr M. de Pourtalés. Joubin (1885) suggested C. anomala , C. pourtalesii and C. rostrata [= turbinata ] might all be varieties of a single species (Emig 2014). Dall (1886) gave general localities for three specimens and omitted the ‘var.’ from the name, raising pourtalesii to a full species, but did not comment on this. Dall (1920, p. 273) listed specimens held in the National Museum of Natural History, Smithsonian Institution, four specimens from three general localities including the type locality, “off the Samboes” (in the Florida Keys). Cooper (1954) provided exact coordinates for a single specimen from Campeche Bank, Gulf of Mexico. Jackson et al. (1971) found specimens living on coral at 60 m and within caves at 10–15 m on the Coast of Jamaica. Cooper (1977) described and figured the type specimens and (inadvertently?) shortened the name to pourtalesi . Several later authors used the shortened version but it is not correct. Cohen et al. (2014) found that molecular analysis placed craniid material identified as ‘ N. pourtalesi ’ from Jamaica and Belize (Central America) into their Tethys clade ( N. turbinata ). All the material identified as N. pourtalesii held in the National Museum of Natural History, Smithsonian Institution ( Table 4) was examined and I recognized two species as being present, N. anomala [= N. pourtalesii type material of Dall] and N. turbinata . It appears that both of these species are present in the Caribbean (specimens of the Caribbean material are figured below). N. pourtalesii is placed into synonymy under N. anomala .

Stratigraphic range. It is difficult to give a stratigraphic range for N. anomala because a) there has been so much confusion as to which specimens are N. anomala and which are N. turbinata and b) there are relatively few fossil specimens attributed to N. anomala in the literature.

In Late Oligocene specimens from France identified as N. anomala (Bitner et al. 2013, fig. 2B–D) the ventral valves appear to have radial canals and a calcitic rostellum (like N. turbinata and species of Ancistrocrania Dall, 1877 ) but the two dorsal valves figured appear to have latent posterior and anterior adductor muscle scars. I have not seen any dorsal valves with latent muscle scars in any Recent Novocrania species (although, such is the morphological variability of this genus, it may exist). With no muscle scars in the dorsal valve the identity of these specimens is problematic.

In Middle Miocene specimens from Bulgaria identified as N. anomala (Bitner & Motchurova-Dekova 2016, fig. 2C–G) the single ventral valve interior appears to have radial canals and and a calcitic rostellum, the two dorsal valve interiors have raised anterior adductor muscle scars and a median process, the single dorsal exterior has small spines/pustules; all morphological features of N. turbinata . Taddei Ruggerio & Taddei (2006, fig. 3.1) identified Quaternary specimens from Italy as N. anomala but the single ventral valve figured did not show the rostellum or any diagnostic features.

N. anomala is herein provisionally restricted to Recent as I am unaware of any fossil material that can confidently be identified as N. anomala . However, the calibrated time-tree (App. Fig. 1 ; Table 3) gives an age of 4.9 Ma for the oldest split between specimens of N. anomala within the Northern (N.E. Atlantic) clade (node F, see below) and the wide Recent geographical range of this species is shown herein ( Fig. 1 ). It seems likely that this species will have a fossil history and the new diagnoses, descriptions and figures of N. anomala and N. turbinata included herein should allow fossil material to be identified.

Localities. N. anomala is known off eastern Greenland, Iceland and Svalbard, along the North Atlantic coast of Denmark, Sweden and Norway, the Faroe Islands, all around the British Isles (Wesenberg-Lund 1941, Brunton & Curry 1979, Thomsen 2001), in the North Atlantic off France (Logan 1979) and Portugal (Gaspard 2003), the Madeira Islands (Logan et al. 2007), the Cape Verde Islands (Logan 1988, 1993), the Seawarte Seamounts south of the Azores (Logan 1998), the Gulf of Mexico (Cooper 1954) and the Caribbean (Dall 1920; Jackson et al. 1971), in many localities in the Mediterranean Sea (Logan 1979; Logan & Long 2001; Taddei Ruggerio 2001; Legac 2012; Rosso et al. 2013; Sánchez-Tocino & Figueroa 2013) and maybe in the Red Sea (Logan et al. 2008 as N. cf anomala ; Zuschin & Mayrhofer 2009 as Novocrania sp.).

Localities are shown in Figure 1 including localities of material examined ( Table 4) and published localities (Appendix 2). Wesenburg-Lund (1941) figured many North Atlantic localities of N. anomala with very large, imprecise markers and did not include lat/long data; approximate locations based on Wesenburg-Lund (1941) are included ( Fig. 1 , Appendix 2).

Type material and type locality. The type specimen of N. anomala is lost. Müller (1776) gave no location for his type specimens, but the title of his monograph suggests that the specimens came from Norway or Denmark (Lee & Brunton 1986).

Material examined. Material was examined from the Mediterranean Sea, the North Atlantic, the coasts of Norway, Scotland, Ireland and the Caribbean, including type material of N. pourtalesii ( USNM 111023) from the National Museum of Natural History, Smithsonian Institute, Washington DC ( Table 4).

Description. The dorsal valves vary in outline through round, sub-round, sub-quadrate, sub-hexagonal and irregular ( Fig. 6A–C). The dorsal valves are conical, the flanks may be concave ( Fig. 6D) or convex, valves may be smooth or have concentric growth lamellae and may be xenomorphic ( Fig. 6A), reproducing the texture of the substrate (observed on specimens attached to mussels from Firth of Lorne, Scotland). The largest dorsal valve examined was 18.5 mm long, 21.6 mm wide and 7.1 mm deep from Oban, Scotland (NHMUK ZB 1796). The valve exterior varies in colour through black, dark brown, reddish brown, light tan, yellowish and white ( Fig. 6C, E). The dorsal posterior adductor scars are sub-round to sub-oval and may be slightly concave or flush with the valve surface ( Fig. 6F–M). The oblique internal muscle scars are sub-round and lie at the lateral edge of the posterior adductor muscle scars ( Fig. 6I). The anterior adductor slow-muscle scars are reniform to U-shaped ( Fig. 6F–N) and the quick-muscle scars form dimples on the concave side. The support structure scars may be flush with the valve surface ( Fig. 6F) or may tilt posterio-medianly ( Fig. 6N) and the small anterior muscle scars often lie on All scale bars 1 mm unless stated otherwise. OU—Geology Museum, University of Otago, Dunedin, New Zealand; USNM— National Museum of Natural History, Smithsonian Institution, Washington, USA.

Abbreviations: aaq —anterior adductor quick-muscle scar, aas —anterior adductor slow-muscle scar, dmc —dorsal mantle canals, oi —oblique internal muscle scar, pa —posterior adductor muscle scar, sam —small anterior muscle scars, ss —support structure scar, ts —tiny septum, xr —xenomorphic ridges.

All scale bars 1 mm unless stated otherwise. NHMUK—Natural History Museum, London; NMNZ—Te Papa Tongarewa, National Museum of New Zealand, Wellington ; OU—Geology Museum, University of Otago, Dunedin, New Zealand ; USNM—National Museum of Natural History , Smithsonian Institution, Washington, USA .

Abbreviations: bw —calcitic ‘batwing’ outline of latent rostellum, dv —dorsal valve, lpa —latent posterior adductor muscle scar, lro —latent rostellum, my —myotest, pap —posterior adductor organic pad, rop —rostellum pad, pu —punctae, rs —rock substrate, tu —tubercles, vv —ventral valve.

each side of, or at the apex of, a tiny median septum ( Fig. 6N). The dorsal mantle canals sometimes leave many thin radial impressions anterior of the anterior adductor muscle scars ( Fig. 6F). The dorsal valve inner surface is densely punctate.

In the ventral valves the posterior adductor muscle attachment surfaces and the rostellum, where the anterior adductor and oblique internal muscles attach, are usually organic pads of muscle attachment tissue ( Fig. 7A–C). In specimens where the pads have decayed away there are latent muscle scars, variably shaped for the latent posterior adductor muscle scars ( Fig. 7D–F) and a characteristic ‘bat-wing’ shape with a calcitic rim for the latent rostellum ( Fig. 7D, E, G, H). The shell surface of the latent muscle scar may be smooth ( Fig. 7F) or irregular ( Fig. 7I) but there is no myotest, the characteristic surface texture of calcitic muscle scars ( Fig. 7J, K). The ventral valves vary in thickness and calcification, ranging from only a thin organic membrane to an outer calcitic ring with varying amounts of organic membrane/calcitic valve in the middle ( Fig. 7G, H) to a fully calcitic valve that may be flat ( Fig. 7D, L) or form a shallow bowl ( Fig. 7A). The valve margins are tuberculate ( Fig. 7D, M) and the valve surface is punctate ( Fig. 7M).

Ecology. N. anomala attaches to hard substrates and is often found in cryptic habitats; in caves in Jamaica (Jackson et al. 1971) and the Mediterranean Sea (Taddei Ruggerio 2001; Legac 2012; Rosso et al. 2013), on or under boulders (Sánchez-Tocino & Figueroa 2013) and on rock walls (Jonsson 2014). N. anomala has a wide depth range; from very shallow water, 30 cm below low tide level in a sea cave at Isca Island, Italy (Taddei Ruggerio 2001) to deep water, 1665 m in the North Atlantic (Logan 1993). N. anomala has been found associated with hydrocarbon seeps in the North Atlantic on “hard crusts, chimneys and slabs” (Rueda et al. 2012, p. 838). Logan (1979) recorded densities of up to 250/m2 on the sides and lower surfaces of boulders on the coast of Malta. A ten year period of observation of live N. anomala in a shallow submarine cave in south Italy suggests that this species may live for 40 years and that for the last part of its life it does not grow any larger (Taddei Ruggiero 2001).

Remarks. Three ventral valves attached to a small rock (NHMUK ZB 3956) had posterior adductor muscle scars with calcitic myotest rather than latent muscle scars, but this appears to be uncommon in N. anomala .

Figures

FIGURE 1. Localities of Novocrania anomala (red dots) and N. altivertex (orange square). Yellow rectangles may be N. anomala or N. turbinata.