Seorsumuscardinus
Seorsumuscardinus Temporal range: Early
MN 4–5 ) | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Rodentia |
Family: | Gliridae |
Subfamily: | Glirinae |
Genus: | †Seorsumuscardinus De Bruijn, 1998 |
Type species | |
Seorsumuscardinus alpinus De Bruijn, 1998
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Species | |
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Localities where Seorsumuscardinus has been found. MN 4 localities (S. alpinus) in red; the single MN 5 locality (S. bolligeri) in blue. | |
Synonyms | |
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Seorsumuscardinus is a
The two species of Seorsumuscardinus are known from isolated teeth, which show that they were medium-sized dormice with flat teeth. The teeth are all characterized by long transverse crests coupled with shorter ones. One of these crests, the
Taxonomy
In 1992, Thomas Bolliger described some teeth of Seorsumuscardinus from the Swiss locality of Tägernaustrasse (
Because of its
Description
Tooth | Measurement | Affalterbach | Oberdorf |
---|---|---|---|
P4 | Length | 1.03 | 0.93–0.97 |
Width | 1.07 | 1.06–11.2 | |
M1 | Length | 1.26 | 1.20–1.29 |
Width | 1.40 | 1.31–1.43 | |
M2 | Length | 1.14–1.22 | 1.21–1.24 |
Width | 1.37–1.50 | 1.33–1.45 | |
M3 | Length | 1.05 | 1.03 |
Width | 1.25 | 1.19 | |
p4 | Length | – | 0.80 |
Width | – | 0.65 | |
m1 | Length | 1.35 | 1.25–1.27 |
Width | 1.28 | 1.26–1.31 | |
m2 | Length | 1.28 | – |
Width | 1.40 | – | |
m3 | Length | – | 1.15–1.28 |
Width | – | 1.06–1.27 | |
All measurements are in millimeters. P4: fourth upper premolar; M1: first upper molar; etc. p4: fourth lower premolar; m1: first lower molar; etc. |
Only the cheek teeth of Seorsumuscardinus are known; these include the fourth premolar and three molars in the upper (maxilla) and lower jaws (mandible).[11] The teeth are medium-sized for a dormouse and have a flat occlusal (chewing) surface.[12] S. bolligeri is slightly larger than S. alpinus.[4]
Upper dentition
The fourth upper premolar (P4) has four main, transversely placed crests;
The first upper molar (M1) was described as square by De Bruijn[14] and as rounded by Prieto and Böhme.[9] There are five main transverse crests,[10] which are mostly isolated, but some may be connected on the borders of the teeth.[15] The middle crest, the centroloph, reaches to the labial (outer) margin in the single known M1 of S. bolligeri, but does not in any of the five M1 of S. alpinus.[16] The front crest, the anteroloph, is less distinct in S. bolligeri than most S. alpinus, but one M1 of S. alpinus is similar to that of S. bolligeri.[4] M1 has three roots in S. alpinus,[13] but the number of roots in S. bolligeri is not known.[17]
Prieto and Böhme describe M2 as less rounded than M1[17] and De Bruijn notes that the crests are more parallel.[18] In addition to the five main crests, small crests are present in front of and behind the centroloph that do not cover the full width of the tooth.[19] In one S. bolligeri M2, there is a small crest on the lingual side in front of the centroloph, but such a crest does not occur in any S. alpinus.[16] Another M2 of S. bolligeri has this crest on the labial side.[17] On the other hand, all five M2 of S. alpinus have a minor crest on the labial side behind the centroloph. In two M2 of S. alpinus, the centroloph and the metaloph are connected by a longitudinal crest, which is never present in S. bolligeri.[16] There are three roots.[20]
M3 is known from a single specimen each from Oberdorf, Affalterbach, and Tägernaustrasse.[21] In addition to the main crests, there are two or three additional smaller crests.[19] The roots are unknown.[17]
Lower dentition
The fourth lower premolar (p4) is known from a poorly preserved specimen from Oberdorf and a less worn specimen from Tägernaustrasse. There are four ridges, of which the front and back pair are connected at the lingual side and in the Oberdorf specimen also at the labial side. This tooth is similar to that of Muscardinus hispanicus, but the front pair is better developed.[18] There is one root.[13]
The first lower molar (m1) bears four main crests and a smaller one between the two crests at the back.
Range
In MN 4, Seorsumuscardinus has been recorded from Oberdorf, Austria (sites 3 and 4, which yielded 6 and 17 Seorsumuscardinus alpinus teeth, respectively); Karydia, Greece (S. alpinus); and Tägernaustrasse, Switzerland (5 teeth; S. cf. alpinus). Affalterbach, Germany, where 10 teeth of S. bolligeri were found, is the only known MN 5 locality.[23] In all these localities, it is part of a diverse dormouse fauna.[24] Because the distributions of the two known species are temporally distinct, Prieto suggested that the genus may be useful for biostratigraphy (the use of fossils to determine the age of deposits).[4] Seorsumuscardinus occurred at the same time as the oldest known Muscardinus.[25]
References
- ^ Bolliger, 1992, p. 129
- ^ De Bruijn, 1998, pp. 111–113; Prieto, 2009, pp. 377, 379; Doukas, 2003, table 2
- ^ Prieto and Böhme, 2007, pp. 303, 305; Prieto, 2009, p. 377
- ^ a b c d e Prieto, 2009, p. 378
- ^ Prieto, 2009, p. 379
- ^ Prieto and Böhme, 2007, p. 306; Prieto, 2009, p. 378
- ^ McKenna and Bell, 1997, pp. 174–178
- ^ Prieto and Böhme, 2007, p. 302
- ^ a b c d e f Prieto and Böhme, 2007, p. 303
- ^ a b c De Bruijn, 1998, p. 112; Prieto and Böhme, 2007, p. 303
- ^ De Bruijn, 1998, p. 110; Prieto and Böhme, 2007, p. 303
- ^ Bolliger, 1992, p. 129; De Bruijn, 1998, p. 111; Prieto and Böhme, 2007, p. 303
- ^ a b c d e f De Bruijn, 1998, p. 112
- ^ De Bruijn, 1998, p. 111
- ^ De Bruijn, 1998, pp. 111–113; Prieto and Böhme, 2007, pp. 303–304
- ^ a b c d e Prieto, 2009, p. 377
- ^ a b c d Prieto and Böhme, 2007, p. 304
- ^ a b c d De Bruijn, 1998, p. 113
- ^ a b De Bruijn, 1998, p. 113; Prieto and Böhme, 2007, p. 304
- ^ De Bruijn, 1998, p. 112; Prieto and Böhme, 2007, p. 304
- ^ De Bruijn, 1998, p. 112; Prieto and Böhme, 2007, p. 303; Bolliger, 1992, p. 129
- ^ a b De Bruijn, 1998, p. 113; Prieto and Böhme, 2007, p. 303
- ^ Prieto, 2009; Bolliger, 1992, p. 128; De Bruijn, 1998, p. 112; Prieto and Böhme, 2007, p. 303
- ^ Bolliger, 1992; De Bruijn, 1998; Doukas, 2003; Prieto and Böhme, 2007
- ^ Prieto and Böhme, 2007, pp. 305–306
Literature cited
- Bolliger, T. 1992. Kleinsäuger aus der Miozänmolasse der Ostschweiz. Documenta Naturae 75:1–296.
- Bruijn, H. de. 1998. Vertebrates from the Early Miocene lignite deposits of the opencast mine Oberdorf (Western Styrian Basin, Austria): 6. Rodentia I (Mammalia). Annalen des Naturhistorischen Museums in Wien 99A:99–137.
- Doukas, C.S. 2003. Las faunas de la MN 4 de Aliveri y Karydia (Grecia). Coloquios de Paleontología, Volúmen Extraordinario 1:127–132.
- McKenna, M.C. and Bell, S.K. 1997. Classification of Mammals: Above the species level. New York: Columbia University Press, 631 pp. ISBN 978-0-231-11013-6
- Prieto, J. 2009. Comparison of the dormice (Gliridae, Mammalia) Seorsumuscardinus alpinus De Bruijn, 1998 and Heissigia bolligeri Prieto & Böhme, 2007 (subscription required). Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 252(3):377–379.
- Prieto, J. and Böhme, M. 2007. Heissigia bolligeri gen. et sp. nov.: a new enigmatic dormouse (Gliridae, Rodentia) from the Miocene of the Northern Alpine Foreland Basin (subscription required). Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 245(3):301–307.