Neoparadoxia

Neoparadoxia Temporal range: Miocene PreꞒ Ꞓ O S D C P T J K Pg N
N. cecilialina holotype at the Natural History Museum of Los Angeles County.
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	† Desmostylia
Family:	† Paleoparadoxiidae
Genus:	† Neoparadoxia Barnes, 2013
Type species
†Neoparadoxia cecilialina Barnes, 2013
Species
N. cecilialinaBarnes, 2013 N. repenningi(Domning and Barnes, 2007)

Life reconstruction of a young Neoparadoxia.

Neoparadoxia is an extinct genus of large, herbivorous aquatic desmostylian mammals from the Miocene Ladera and Monterey Formations of North America.The name comes from the Latin "Neo", meaning new, and Paleoparadoxia , a related genus of desmostylian. ^[1]

Description

Cranium of the holotype of Neoparadoxia.

Neoparadoxia has thicker tooth enamel than other desmostylian genera. The genus also has high-crowned molars, with extra cusps. ^[2] The first and second premolars are also proportionally larger. Neoparadoxia bears 3 pairs of mesosterna (as opposed to the typical 4). ^[1] The humeral morphology is similar to other paleoparadoxiids, with a thick shaft. ^{[3] [1]} The body size of Neoparadoxia is speculated to be larger than other desmostylians, with species varying in length from 2.2 meters to 2.73 meters. ^[1] Like other desmostylians, Neoparadoxia was primarily aquatic ^[4] , though research has suggested it was capable of some terrestrial locomotion. The genus is suggested to have moved like chalicotheres whilst on land. ^[5]

Classification

Neoparadoxia is grouped within the family Paleoparadoxiidae, alongside the related genera Archaeoparadoxia and Paleoparadoxia . ^[6]

Phylogeny of Paleoparadoxiidae, according to Barnes (2013); ^[1]

	Behemotops
	Archaeoparadoxia Paleoparadoxia Neoparadoxia

References

1. Lawrence G Barnes (2013). A New Genus and Species of Late Miocene Paleoparadoxiid (Mammalia, Desmostylia) from Calieornia.
2. Matsui, Kumiko; Valenzuela-Toro, Ana M.; Pyenson, Nicholas D. (2022-08-21). "New data from the first discovered paleoparadoxiid (Desmostylia) specimen shed light into the morphological variation of the genus Neoparadoxia". Scientific Reports. 12 (1): 14246. Bibcode:2022NatSR..1214246M. doi:10.1038/s41598-022-18295-5. ISSN   2045-2322.
3. Matsui, Kumiko (2017-11-10). "How can we reliably identify a taxon based on humeral morphology? Comparative morphology of desmostylian humeri". PeerJ. 5 e4011. doi: 10.7717/peerj.4011 . ISSN   2167-8359. PMC   5683048 . PMID   29134151.
4. Domning, Daryl P. (2018-01-01), "Desmostylia", in Würsig, Bernd; Thewissen, J. G. M.; Kovacs, Kit M. (eds.), Encyclopedia of Marine Mammals (Third Edition), Academic Press, pp. 250–253, ISBN   978-0-12-804327-1 , retrieved 2025-10-16
5. Matsui, Kumiko; Sashida, Katsuo; Agematsu, Sachiko; Kohno, Naoki (2017-04-01). "Habitat preferences of the enigmatic Miocene tethythere Desmostylus and Paleoparadoxia (Desmostylia; Mammalia) inferred from the depositional depth of fossil occurrences in the Northwestern Pacific realm". Palaeogeography, Palaeoclimatology, Palaeoecology. 471: 254–265. Bibcode:2017PPP...471..254M. doi:10.1016/j.palaeo.2017.02.005. ISSN   0031-0182.
6. Matsui, Kumiko; Tsuihiji, Takanobu (2019-10-17). "The phylogeny of desmostylians revisited: proposal of new clades based on robust phylogenetic hypotheses". PeerJ. 7 e7430. doi: 10.7717/peerj.7430 . ISSN   2167-8359. PMID   31637114.