Paleoparadoxia Explained

Paleoparadoxia ("ancient paradox") is a genus of large, herbivorous aquatic mammals that inhabited the northern Pacific coastal region during the Miocene epoch . It ranged from the waters of Japan (Tsuyama and Yanagawa), to Alaska in the north, and down to Baja California, Mexico.

Description

Paleoparadoxia is thought to have fed primarily on seaweeds and sea grasses. The jaws and the angle of the teeth resemble a backhoe bucket. Its bulky body was well adapted for swimming and underwater foraging. Originally interpreted as amphibious, Paleoparadoxia is now thought to have been a fully marine mammal like their living relatives, the sirenians, spending most of their lives walking across the sea bottom like marine hippos. Studies on its habitat preference show that it favoured deep, offshore waters.^[1]

Recent discoveries have extended the known geographical range of Paleoparadoxia, with the oldest record from the northwest Pacific suggesting a much earlier presence in this region. This finding implies that Paleoparadoxia had a wider distribution and potentially different migratory patterns than previously understood, hinting at a complex early evolution within the Desmostylia order.^[2]

Size estimates of P. tabatai vary, with the Tsuyama specimen measuring in length, in height, and in body mass, and the other specimens measuring and 3.2MT in body mass.^[3]

named the genus Cornwallius but synonymized it as a species of Paleoparadoxia.^[4]

See also

• Behemotops
• Desmostylus
• Tethytheria

Bibliography

• Clark . J. M. . A new early Miocene species of Paleoparadoxia (Mammalia: Desmostylia) from California . 1991 . Journal of Vertebrate Paleontology . 11 . 4 . 490–508 . 4908959659 . 10.1080/02724634.1991.10011417. 1991JVPal..11..490C .
• Domning . D. P. . Barnes . L. G. . A new name for the 'Stanford Skeleton' of Paleoparadoxia (Mammalia, Desmostylia) . 2007 . Journal of Vertebrate Paleontology . 27 . 3 . 748–751 . 4630515072 . 10.1671/0272-4634(2007)27[748:annfts]2.0.co;2. 86342777 .
• Hayashi . Shoji . Houssaye . Alexandra . Nakajima . Yasuhisa . Chiba . Kentaro . Ando, Tatsuro . Sawamura, Hiroshi . Inuzuka, Norihisa . Kaneko, Naotomo . Osaki, Tomohiro . Bone Inner Structure Suggests Increasing Aquatic Adaptations in Desmostylia (Mammalia, Afrotheria) . 2013 . PLOS ONE . 8 . 4 . e59146 . 10.1371/journal.pone.0059146 . 23565143 . 3615000. 2013PLoSO...859146H . free .
• Inuzuka . Norihisa . The Stanford Skeleton of Paleoparadoxia (Mammalia: Desmostylia) . 2005 . Bulletin of the Ashoro Museum of Paleontology . 3 . 3–110 .
• Book: Kemp, Tom S. . The Origin and Evolution of Mammals . 2005 . Oxford University Press . 0198507615 . 56652579 .
• Reinhart . Roy Herbert . A review of the Sirenia and Desmostylia . 1959 . University of California Publications in Geological Sciences . 36 . 1 . 1–146 . 3474601 .
• Book: Tokunaga, Shigeyasu<!-- formerly Yoshiwara, Shigeyasu --> . A new fossil mammal belonging to the Desmostylidae . Jubilee publication commemorating Prof. H. Yabe, M.I.A. sixtieth birthday . 1939 . Sendai (Japan). Tohoku Imperial University, Inst. Geol. Pal. . 1 . 289–299 . 11 March 2013 .

Notes and References

1. Kumiko Matsui . Katsuo Sashida . Sachiko Agematsu . Naoki Kohno . 1 April 2017 . 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 . 471 . 254–265 . 10.1016/j.palaeo.2017.02.005 . 2017PPP...471..254M . 0031-0182.
2. Matsui . Kumiko . Kawabe . Soichiro . July 2015 . The Oldest Record of Paleoparadoxia from the Northwest Pacific with an Implication on the Early Evolution of Paleoparadoxiinae (Mammalia: Desmostylia) . Paleontological Research . 19 . 3 . 251–265 . 10.2517/2015PR007 . 1342-8144.
3. Inuzuka, N. (1996). Body size and mass estimates of desmostylians(Mammalia). The Journal of the Geological Society of Japan, 102(9), 816–819. https://doi.org/10.5575/geosoc.102.816
4. Web site: OPINION 2232 (Case 3384) Cornwallius tabatai Tokunaga, 1939 (currently Paleoparadoxia tabatai; Mammalia, Desmostylia): proposed designation of a neotype not accepted . ICZN . 11 March 2013.