Megachasma applegatei

Megachasma applegatei Temporal range: Chattian–Aquitanian PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Chondrichthyes
Subclass:	Elasmobranchii
Order:	Lamniformes
Family:	Megachasmidae
Genus:	Megachasma
Species:	†M. applegatei
Binomial name
†Megachasma applegatei Shimada, Welton and Long, 2014

Megachasma applegatei is an extinct species of megamouth shark from the Oligocene to early Miocene (28-23 Mya) of the Western United States.[1][2] The type fossil was discovered in the San Joaquin Valley in 1973, but only described in 2014, when the species was named after its discoverer, Shelton Applegate.[3]

Description

Megachasma applegatei is only known from isolated teeth. Based on comparison with the teeth of the recent species (Megachasma pelagios), it was approximately 6 m long and, like modern megamouth sharks, probably fed on fish and small planktonic invertebrates both in deep and shallow water habitats. Its teeth had shorter crowns and a pair of side cusplets.[4] The teeth were also more variable in shape than the modern megamouth's, and may have been arranged in the distinctive heterodont "lamnoid tooth pattern" seen in predatory lamniform sharks.[5]

References

1. "†family Megachasmidae (mackerel shark)". PBDB.
2. "Megachasma applegatei SHIMADA, WELTON & LONG, 2014". Shark reference.com.
3. "A Forgotten Fossil Megamouth Gets a Name". National Geographic. Archived from the original on May 14, 2019.
4. Shimada, K.; Welton, B. J.; Long, D. J. (2014). "A new fossil megamouth shark (Lamniformes, Megachasmidae) from the Oligocene-Miocene of the western United States". Journal of Vertebrate Paleontology. 34 (2): 281–290. Bibcode:2014JVPal..34..281S. doi:10.1080/02724634.2013.803975. S2CID 83949683.
5. Krak, Alexandra M.; Shimada, Kenshu (2023). "The dentition of the extinct megamouth shark, Megachasma applegatei (Lamniformes: Megachasmidae), from southern California, USA, based on geometric morphometrics". PaleoBios. 40 (1). doi:10.5070/P940160139. ISSN 0031-0298.