Cynthiacetus

Cynthiacetus is an extinct genus of basilosaurid early whale that lived during the Late Eocene (Bartonian-Priabonian, 40.4 to 33.9 million years ago.)^[1] Specimens have been found in the southeastern United States and Peru (Otuma Formation).^[2]

Cynthiacetus Temporal range: Late Eocene ~40.4–33.9 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Skeleton at the MNHN, Paris
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Artiodactyla
Infraorder:	Cetacea
Family:	†Basilosauridae
Subfamily:	†Dorudontinae
Genus:	†Cynthiacetus Uhen 2005
Species
†C. maxwelli (type) Uhen 2005 †C. peruvianus Martínez-Cáceres & de Muizon 2011

Discovery and naming

Skull of C. peruvianus at the MNHN, Paris

Cynthiacetus was named after the town of Cynthia, Mississippi, close to where the type specimen for the species C. maxwelli was discovered.

Description

Life restoration

The skull of C. maxwelli was similar in size and morphology to that of Basilosaurus cetoides, but Cynthiacetus lacked the elongated vertebrae of Basilosaurus. Uhen 2005 erected the genus to avoid the nomen dubium Pontogeneus (which was based on poorly described and now vanished specimens).^[3] Cynthiacetus was smaller than Masracetus.^[4]

The South American species C. peruvianus, the first archaeocete to be described on that continent, mainly differs from C. maxwelli in the number of cuspids in the lower premolars, but it also has the greatest numbers of thoracic vertebrae (20).^[2] The type specimen of C. peruvianus belonged to an adult individual measuring 9 m (30 ft) long.^[5]

References

• Cetaceans portal
• Paleontology portal
• Peru portal

1. Cynthiacetus maxwelli in the Paleobiology Database. Retrieved July 2013.
2. Martínez-Cáceres & de Muizon 2011, Abstract
3. Uhen 2008, p. 93
4. Gingerich 2007, p. 375
5. Martínez-Cáceres, M.; Lambert, O.; De Muizon, C. (2017). "The anatomy and phylogenetic affinities of Cynthiacetus peruvianus, a large Dorudon-like basilosaurid (Cetacea, Mammalia) from the late Eocene of Peru" (PDF). Geodiversitas, Museum National d'Histoire Naturelle Paris. 39 (1): 7–163. doi:10.5252/g2017n1a1. S2CID 90142285.

Bibliography

• Gingerich, Philip D (2007). "Stromerius nidensis, new archaeocete (Mammalia, Cetacea) from the Upper Eocene Qasr El-Sagha Formation, Fayum, Egypt" (PDF). Contributions from the Museum of Paleontology. 31 (13): 363–378. OCLC 214233870.
• Martínez-Cáceres, Manuel; de Muizon, Christian (2011). "A new basilosaurid (Cetacea, Pelagiceti) from the Late Eocene to Early Oligocene Otuma Formation of Peru". Comptes Rendus Palevol. 10 (7): 517–526. Bibcode:2011CRPal..10..517M. doi:10.1016/j.crpv.2011.03.006. OCLC 802202947.
• Uhen, Mark D. (2005). "A new genus and species of archaeocete whale from Mississippi". Southeastern Geology. 43 (3): 157–172.
• Uhen, Mark D. (2008). "Basilosaurids". In Perrin, William F.; Wursig, Bernd J.; Thewissen, J.G.M. (eds.). Encyclopedia of Marine Mammals (2 ed.). Academic Press. pp. 91–94. ISBN 978-0-12-373553-9.