First Cretaceous fish fauna from Malaysia

ABSTRACT

Cretaceous fish fossils are reported from Malaysia for the first time. They were found with dinosaur and turtle remains in nonmarine sediments in the interior of Pahang State, Peninsular Malaysia. This fish assemblage consists mostly of isolated teeth, with minor amounts of noncranial remains, including vertebral centra, scales, coprolites, and hybodont fin spines. Over 100 fish teeth were examined. Nine taxa were confirmed from this fish assemblage: six (identified and unidentified) species of hybodont sharks, Heteroptychodus kokutensis, Isanodus paladeji, Lonchidion aff. khoratensis, Mukdahanodus aff. trisivakulii, Egertonodus sp., and Hybodontidae indet., and three species of actinopterygians (ray-finned fishes): ‘Lepidotes’ sp., Halecomorphi indet., and Ginglymodi indet. This fish assemblage has strong affinities with Early Cretaceous (Barremian–early Aptian) faunas of Thailand, because the four hybodont species, H. kokutensis, I. paladeji, L. khoratensis, and M. trisivakulii, were previously known only from the Sao Khua Formation (Khorat Group) and equivalent strata of Ko Kut (Kut Island). Egertonodus has been confirmed in Asia for the first time. Overall, this fish assemblage shows a close linkage to Early Cretaceous (Barremian–early Aptian) faunas of Thailand. Based on faunal composition and biostratigraphic correlation, we suggest a Barremian–early Aptian age for this new fauna from Malaysia.

ACKNOWLEDGMENTS

S. Suteethorn and other members of the Palaeontological Research and Education Centre (PRC) and U. Deesri and K. Lauprasert of the Department of Biology, all in Mahasarakham University, are thanked for facilitating our study of the Thai specimens in the PRC. L. Cavin from the Natural History Museum of Geneva (Switzerland) is thanked for providing helpful information on the fish taxonomy. T. F. Ng (University of Malaya) is also thanked for assisting in the digital single-lens reflex photography of the Malaysian specimens. C. Duffin and G. Guinot are thanked for reviewing the manuscript and giving valuable comments. All SEM images in this paper were produced with the FESEM in the Institute of Biological Science (ISB), University of Malaya. Permissions to reproduce some published photographs were kindly granted by Elsevier, Taylor & Francis, and Wiley. This study was part of T.Y.H.’s M.Sc. project at the University of Malaya, which was funded partly by a PPP Postgraduate Research Grant (PG190-2014). IGCP608 (Asia-Pacific Cretaceous Ecosystems) also provided a Grant-in-Aid to T.Y.H.

ORCID

Masatoshi Sone http://orcid.org/0000-0001-9738-5581

Ren Hirayama http://orcid.org/0000-0002-0823-5272

Gilles Cuny http://orcid.org/0000-0001-7680-1697