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]

Megachasma applegatei
Temporal range: Chattian–Aquitanian
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Subdivision: Selachimorpha
Order: Lamniformes
Family: Megachasmidae
Genus: Megachasma
Species:
M. applegatei
Binomial name
Megachasma applegatei
Shimada, Welton and Long, 2014

Description edit

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 edit

  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.