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Pelagic neonatal fossils support viviparity and precocial life history of C retaceous mosasaurs
Author(s) -
Field Daniel J.,
LeBlanc Aaron,
Gau Adrienne,
Behlke Adam D.
Publication year - 2015
Publication title -
palaeontology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.69
H-Index - 63
eISSN - 1475-4983
pISSN - 0031-0239
DOI - 10.1111/pala.12165
Subject(s) - pelagic zone , biology , apex predator , paleontology , fishery , predation
Mosasaurs were large marine squamates that inhabited all of the world's oceans during the L ate C retaceous. Their success as apex predators has been attributed to their rapid acquisition of aquatic adaptations, which allowed them to become fully pelagic. However, little is known about the breeding biology of derived, flipper‐bearing mosasaurs, as the record of neonatal mosasaur fossils is extremely sparse. Here, we report on the fragmentary cranial remains of two neonatal mosasaurs from the N iobrara F ormation, referred to C lidastes sp. Comparison with other preliminary reports of neonatal mosasaurs reveals that these specimens are among the smallest individuals ever found and certainly represent the smallest known C lidastes specimens. The recovery of these extremely young specimens from a pelagic setting indicates that even neonatal mosasaurs occupied open oceanic habitats and were likely born in this setting. These data shed new light on the ecology of neonatal mosasaurs and illustrate the degree to which size‐related taphonomic and collection biases have influenced our understanding of the early life history of these iconic marine reptiles.