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A skull of proargyrolagus, the oldest argyrolagid (late oligocene salla beds, bolivia), with brief comments concerning its paleobiology

Publication ,  Journal Article
Sánchez-Villagra, MR; Kay, RF
Published in: Journal of Vertebrate Paleontology
January 1, 1997

A skull of the oldest described argyrolagid, Proargyrolagus bolivianus (late Oligocene of the Salla Beds, Bolivia) allows an assessment of the phylogeny of this group and a reconstruction of its paleobiology. Several aspects of the cranial anatomy of the Monodelphis-sized Proargyrolagus serve to support the hypothesis that argyrolagids are marsupials: the palate has large vacuities, the angular process is medially inflected, the auditory bulla is composed of a wing of the alisphenoid, and the dental formula includes four molars. Like Argentine Plio-Pleistocene argyrolagids, Proargyrolagus has an unfused symphysis, and a phaneric and almost vertically oriented ectotympanic in the shape of a flattened ring. Proargyrolagus is more primitive in having a less globular braincase, smaller orbits, and a shallower mandible. The dental formula is 4/3.1/1.3/2.4/4 or 4/4.1/0.3/2.4/4 (vs. 2/2.0/0.1/1.4/4 for Argyrolagus). Large infraorbital foramina transmitted nerves and vessels of the snout. The snout is long with the nasals projecting well forward of the incisors and with a strong antorbital fossa for facial muscles. It can be inferred that this animal had well-developed vibrissae and a mobile proboscis, and relied heavily on its rostrum to gather tactile information. Food manipulation was assisted by an elongate, procumbent lower incisor that occluded with three sharply-edged upper incisors, as in living phalangeriform marsupials. Like Plio-Pleistocene argyrolagids and extant elephant shrews, Proargyrolagus has prismatic and high crowned cheek teeth suggesting an abrasive diet consisting perhaps of seeds. © 1997 by the society of vertebrate paleontology.

Duke Scholars

Published In

Journal of Vertebrate Paleontology

DOI

EISSN

1937-2809

ISSN

0272-4634

Publication Date

January 1, 1997

Volume

17

Issue

4

Start / End Page

717 / 724

Related Subject Headings

  • Paleontology
  • 3705 Geology
  • 3104 Evolutionary biology
  • 0603 Evolutionary Biology
  • 0602 Ecology
  • 0403 Geology
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Sánchez-Villagra, M. R., & Kay, R. F. (1997). A skull of proargyrolagus, the oldest argyrolagid (late oligocene salla beds, bolivia), with brief comments concerning its paleobiology. Journal of Vertebrate Paleontology, 17(4), 717–724. https://doi.org/10.1080/02724634.1997.10011019
Sánchez-Villagra, M. R., and R. F. Kay. “A skull of proargyrolagus, the oldest argyrolagid (late oligocene salla beds, bolivia), with brief comments concerning its paleobiology.” Journal of Vertebrate Paleontology 17, no. 4 (January 1, 1997): 717–24. https://doi.org/10.1080/02724634.1997.10011019.
Sánchez-Villagra MR, Kay RF. A skull of proargyrolagus, the oldest argyrolagid (late oligocene salla beds, bolivia), with brief comments concerning its paleobiology. Journal of Vertebrate Paleontology. 1997 Jan 1;17(4):717–24.
Sánchez-Villagra, M. R., and R. F. Kay. “A skull of proargyrolagus, the oldest argyrolagid (late oligocene salla beds, bolivia), with brief comments concerning its paleobiology.” Journal of Vertebrate Paleontology, vol. 17, no. 4, Jan. 1997, pp. 717–24. Scopus, doi:10.1080/02724634.1997.10011019.
Sánchez-Villagra MR, Kay RF. A skull of proargyrolagus, the oldest argyrolagid (late oligocene salla beds, bolivia), with brief comments concerning its paleobiology. Journal of Vertebrate Paleontology. 1997 Jan 1;17(4):717–724.

Published In

Journal of Vertebrate Paleontology

DOI

EISSN

1937-2809

ISSN

0272-4634

Publication Date

January 1, 1997

Volume

17

Issue

4

Start / End Page

717 / 724

Related Subject Headings

  • Paleontology
  • 3705 Geology
  • 3104 Evolutionary biology
  • 0603 Evolutionary Biology
  • 0602 Ecology
  • 0403 Geology