Vasseuromys cristinae, Ruiz-Sánchez & Murelaga & Freudenthal & Larrasoaña & Garcés, 2012
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publication ID |
https://doi.org/ 10.4202/app.2010.0081 |
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persistent identifier |
https://treatment.plazi.org/id/03F06B06-7338-FF9F-8A77-82AB22A9FE5C |
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treatment provided by |
Felipe |
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scientific name |
Vasseuromys cristinae |
| status |
sp. nov. |
Vasseuromys cristinae sp. nov.
Fig. 4.
Etymology: Named after Cristina Marzo, stepdaughter of the first author.
Holotype: PF2−81, isolated left m1.
Type locality: Pico del Fraile 2 (PF2), Ebro Basin, Spain.
Type horizon: 15.8 Ma, Lower–Middle Aragonian, Middle Miocene.
Referred material.—2 p4 (PF2−103; PF2−104), 8 m 1 (PF2−81; PF2−82; PF2−84; PF2−85; PF2−86; PF2−87; PF2−108; PF2− 109), 7 m 2 (PF2−89; PF2−90; PF2−91; PF2−92; PF2−93; PF2− 94; PF2−95), 5 m 3 (PF2−97; PF2−98; PF2−99; PF2−100; PF2− 101), 1 dP4 (PF2−80), 2 P4 (PF2−78; PF2−79), 11 M1 (PF2−61; PF2−63; PF2−64; PF2−65; PF2−66; PF2−68; PF2−69; PF2−70; PF2−72; PF2−74; PF2−113), 4 M2 (PF2−62; PF2−67; PF2−71; PF2−73), 3 M3 (PF2−76; PF2−77; PF2−111).
Diagnosis.—Medium−sized species of Vasseuromys . Lower molars with four extra ridges: anterotropid, extra ridge between metalophid and centrolophid, second centrolophid, and posterotropid; metalophid mostly connected to the metaconid, and mesolophid to the entoconid; posterotropid connected to posterolophidł M1–2 with incomplete endoloph; M1–2 without extra ridges outside the trigone and three on the inside (prototrope, metatrope, and medium−sized and elongated mesostyle between pre− and postcentroloph).
Differential diagnosis.— Vasseuromys cristinae sp. nov. differs from V. autolensis , V. priscus , V. rugosus , V. bacchius , V. elegans , and V. pannonicus in: presence of four extra ridges on m1–3; posterotropid always single; differs from V. duplex in: single anterotropid; posterotropid connected to the posterolophid; differs from V. bacchius and V. pannonicus in: metalophid connected to the metaconid; differs from V. priscus and V. rugosus in: higher frequency of specimens with a mesolophid–entoconid connection; differs from V. autolensis , V. priscus , V. duplex , and V. pannonicus in: constant presence of three extra ridges inside the trigone on M1–2; differs from V. autolensis , V. priscus , V. bacchius , and V. rugosus in: much higher frequency of M1–2 with anteroloph and posteroloph connected to the paracone and metacone, respectively; differs from V. pannonicus in: presence of divided paracone on M1–2; differs from V. rugosus , V. bacchius , and V. pannonicus in: M2 with long prototrope connected to the precentroloph; differs from V. bacchius in: anteroloph of M3 connected to the paracone; differs from V. autolensis in: lower frequency of anterotrope on M3 (33% vs. 65%); differs from all other species of Vasseuromys in: complete absence of endoloph on M1–2. With respect to size, V. cristinae sp. nov. is smaller than V. bacchius , larger than V. duplex and V. elegans , and similar to the remaining members of the genus ( Figs. 5 View Fig , 6 View Fig ).
Measurements.—See Table 1.
Description
p4.—The anterolophid is connected to the protoconid. The centrolophid is long and connected to an external wall along the labial border of the tooth (n = 1), or of medium size and not connected to this external wall (n = 1). The labial cusps are elongated anteriorly. The prominent ectolophid is interrupted between the mesolophid and the posterolophid. One out of two specimens has a posterior branch of the hypoconid, forming a tiny valley with the posterolophid behind the hypoconid ( Fig. 4A). Both specimens have an extra ridge between the
RUIZ−SÁNCHEZ ET AL.—NEW MIOCENE GLIRID RODENT FROM SPAIN 229
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metalophid and the centrolophid, a second centrolophid, and a posterotropid.
m1.—The anterolophid is either connected to the protoconid at a high level, or a tiny and shallow furrow is present between them ( Fig. 4D). The metalophid is connected to the metaconid at either a high or a low level. In two of the specimens the centrolophid is double, with both ridges having at least one connection; in another specimen, the centrolophid is connected to the labial part of the metalophid, whereas it fuses at the labial border with the anterior prolongation of the mesoconid in five others ( Fig. 4D). The mesolophid is connected to the entoconid. The labial part of the posterolophid is elongated longitudinally and separated from the mesoconid. The posterotropid is long and usually connected to the anterolingual part of the posterolophid (n = 7), with only one specimen lacking this connection. There are generally four extra ridges: an anterotropid (not present in one of the seven specimens), a ridge between the metalophid and the centrolophid, a second centrolophid, and a posterotropid. The posterior centrolophid either ends free, or is connected to the entoconid and/or lingual part of the centrolophid. The posterior centrolophid is of medium size ( Fig. 4E) or long. It is generally isolated (n = 5), but can also be connected to the anterior centrolophid (n = 2) or labially fused to the elongated part of the mesoconid (n = 1).
m2.—In unworn specimens, the anterolophid is connected to the protoconid at either a high (n = 4) or a low level (n = 1). The metalophid is connected to the metaconid in four specimens, but unconnected in another two. The centrolophid is long, and either fused to the anterior prolongation of the mesoconid (n = 4) ( Fig. 4G), or connected to the latter at a low level ( Fig. 4F). The mesolophid is connected to the entoconid. The posterolophid curves and becomes lower along the labial border, either closely approaching the mesoconid (n = 4), or being connected to it (n = 2). In two specimens, the labial end of the posterolophid is attached to the mesoconid at a low level ( Fig. 4G). Four extra ridges are present, including an anterotropid, a ridge between metalophid and centrolophid, a second
http://dx.doi.org/10.4202/app.2010.0081
centrolophid, and a posterotropid. The connection (at a high or a low level) of the lingual part of the posterior centrolophid to these ridges forms a nearly continuous endolophid ( Fig. 4G). At the lingual border of the tooth, the posterior centrolophid is connected to the anterior centrolophid at a high level, whereas it is connected to the mesolophid at either a high or a low level, thus closing the central valley in several specimens. The posterotropid is long and reaches the labial portion of the posterolophid without being connected (n = 4) ( Fig. 4G), or being connected to the latter at a low level (n = 2) ( Fig. 4F). The posterotropid is connected to the anterolingual portion of the posterolophid at a low level (n = 5), or a tiny and shallow furrow separates both ridges.
m3.—The anterolophid is connected to the protoconid at either a high (n = 4) or a low (n = 1) level. The metalophid is connected to the metaconid. The centrolophid is long and fused to the anterior prolongation of the mesoconid (n = 3), not connected to the mesoconid (n = 1), or connected to the posterior part of the metalophid (n = 1). In one specimen, there is a longitudinal ridge connecting the centrolophid and mesolophid. The mesolophid is connected to the entoconid. In one specimen, the posterolophid is labially connected to the mesoconid. There are four extra ridges, including an anterotropid, a ridge between the metalophid and centrolophid, a second centrolophid, and a posterotropid. The second centrolophid and the extra ridge between the metalophid and centrolophid are short, with the latter usually being connected to the anterior part of the centrolophid. As on m2, the endolophid is nearly continuous ( Fig. 4H). The posterotropid is lingually connected to the posterolophid ( Fig. 4H).
dP4.—The anteroloph is connected to the protocone at a low level, while making contact with the paracone at a higher level ( Fig. 4J). Both the metaloph and the strongly curved protoloph are connected to the protocone. The postcentroloph is strongly curved and connected to the protocone. The metaloph is connected to the protocone. The postcentroloph is of medium size. Only the lingual part of the precentroloph, which is situated in the central valley, is developed. The prototrope is absent. There is a relatively long metatrope, connected to the lingual end of the postcentroloph. The posteroloph is connected to the metacone and protocone.
P4.—The anteroloph is connected to the protocone at a low level. The anteroloph is labially connected to the paracone. The protoloph and metaloph are connected to the protocone. The precentroloph is either relatively long (n = 1) ( Fig. 4L) or short (n = 1) ( Fig. 4K), whereas the postcentroloph is long. The extra ridges are reduced to a short metatrope. The posteroloph is long and connected to the protocone.
M1.—The anteroloph is long and extends to the protocone without forming an endoloph. In unworn specimens, the paracone is divided into two cusps. The anterior cusp of the paracone continues into the protoloph ( Fig. 4M, N), while the posterior cusp fuses with the precentroloph–prototrope complex. The centrolophs are long, with the precentroloph usually being longer than the postcentroloph ( Fig. 4N). Generally there are three extra ridges, including a prototrope, a ridge between the precentroloph and postcentroloph, and a metatrope. Some specimens possess additional low extra ridges running parallel to the main ones ( Fig. 4M). In some specimens, the union between the centrolophs and the extra ridge complex forms an irregular pattern ( Fig. 4M). The metaloph is oriented transversely and connected to the protocone. There are no extra ridges outside the trigone. In unworn specimens, the posteroloph is connected to the protocone and metacone. A shallow furrow separates the labial end of the posteroloph and the metacone in some specimens ( Fig. 4N).
M2.—The anteroloph is long, connected to the paracone, and connected to the protocone at a low level without forming an endoloph. The paracone shows a slight division into two cusps ( Fig. 4P). The centrolophs are long, with the precentroloph being the longer one. There are three extra ridges, including a prototrope, a ridge between the precentroloph and postcentroloph, and a metatrope. The prototrope is very long and runs parallel to the precentroloph until they become connected near the protocone ( Fig. 4O). Other longitudinal connections between both ridges are present. No extra ridges are found outside the trigone. The metaloph is transversely oriented and connected to the protocone and paracone, whereas the posteroloph is connected to the protocone and metacone.
M3.—The anteroloph is connected to the paracone and not connected to the protocone in one complete specimen ( Fig. 4Q), while being connected to the latter at a low level in another one ( Fig. 4R). The centrolophs are long. As on M2, there are three extra ridges and, in addition, one of the three specimens has a very short anterotrope. The connections between the centrolophs and the extra ridges form an irregular ridge pattern ( Fig. 4R). The metacone is divided into several cusps, giving rise to the posterior centroloph and the metaloph ( Fig. 4R). The posteroloph is connected to the protocone.
Geographic and stratigraphic range.—Pico del Fraile 2 (PF2) (MN4/5), Ebro Basin ( Spain).
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