Kolponomos

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Kolponomos
Temporal range: Early Miocene
Skull
Mandible
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Amphicynodontidae
Genus: Kolponomos
Stirton, 1960
Species
  • K. clallamensis Stirton, 1960
  • K. newportensis Tedford et al., 1994

Kolponomos is an extinct

carnivoran mammal that existed in the Late Arikareean North American Land Mammal Age, early Miocene epoch, about 20 million years ago. It was likely a marine mammal.[1] The genus was erected in 1960 by Ruben A. Stirton, a paleontologist at the University of California Museum of Paleontology, Berkeley, for the species K. clallamensis, on the basis of a partial skull and jaw found on the Olympic Peninsula. At the time, Stirton questionably assigned it to Procyonidae, its systematic position remained problematic until the discovery of more fossils including a nearly complete cranium from the original locality of K. clallamensis which helped identify it as part of the group from which pinnipeds evolved.[2]

Description

In life, species of Kolponomos had downturned snouts and broad, heavy molars that would have been suited to a diet of hard-shelled marine invertebrates, and their narrow snouts and anteriorly directed eyes indicate that they would have had stereoscopic vision.[2] Large neck muscle attachments and robust foot bones combine with these features to suggest that Kolponomos filled a unique niche among marine carnivores, approached today only by the very distantly related sea otter. Due to the lack of a complete skeleton, however, it is difficult to make inferences about this genus' other adaptations.

An artist's restoration of an otter-like K. newportensis compared to a human

Based on the skull and jaws known, Kolponomos

sabretooth Smilodon. The anterior portion of the jaw becomes a functional anchoring fulcrum in both Kolponomos and Smilodon. Although dental morphology and heavy occlusal wear patterns are shared with the sea otter. Kolponomos' dentition was less efficient but exhibited higher stiffness than in the sea otter.[1] Riley Black wrote that Kolponomos bit like a sabrecat, crunched like a bear.[3]

Aspects of its feeding morphology were similar to the giant otter Siamogale melilutra, although Kolponomos is not an otter[4]

Discovery

Kolponomos clallamensis is known from the

NALMA.[8]

Kolponomos newportensis was described in 1994 by

tectonic stress, the paleontological laboratory at the Smithsonian Institution considered them "the most difficult materials ever encountered by our laboratory.,"[9] and a combination of techniques proved essential to its extraction and preparation, which lasted two decades. Discovery of K. newportensis disproved the earlier hypothesis that the genus was related to the ancestors of raccoons, and instead was a stem-pinniped.[2][10][11]

References

  1. ^ .
  2. ^ a b c Tedford, R. H.; Barnes, L. G.; Ray, C. E. (1994). "The early Miocene littoral ursoid carnivoran Kolponomos: Systematics and mode of life" (PDF). Proceedings of the San Diego Society of Natural History. 29: 11–32. Archived from the original (PDF) on 22 September 2012. Retrieved 24 July 2010.
  3. ^ "Prehistoric Animal Bit Like a Sabercat, Crunched Like a Bear". Science. 2016-03-03. Archived from the original on May 12, 2019. Retrieved 2019-12-07.
  4. PMID 29123190
    .
  5. ^ "Kolponomos clallamensis". Fossilsworks. Retrieved 17 December 2021.
  6. ^ "Slip Point Lighthouse (Miocene of the United States)". Fossilworks. Retrieved 17 December 2021.
  7. OCLC 692426
    .
  8. . Retrieved 30 December 2013.
  9. .
  10. .
  11. .

External links