Jurassic fishes from the Latady Group, Antarctic Peninsula, and the oldest teleosts from Antarctica

ABSTRACT

The few records of Jurassic fishes from Antarctica comprise several actinopterygians. Here we describe the first fish material recovered from the Latady Group, upper Middle to lower Upper Jurassic southern Antarctic Peninsula—one indeterminate actinopterygian and two teleosts, including a Leptolepidae indet. The content of the family Leptolepidae is revised and the assignment of Leptolepidae indet. to family level is based on three uniquely derived characters proposed here (vertebrae with thin and smooth autocentra; autocentra and chordacentra not constricting the notochord; and lack of cavities for adipose tissue in the walls of the autocentra). The new finding changes previous interpretations that Leptolepidae s. str. is a Northern Hemisphere family. The presence of Middle Jurassic leptolepids in Antarctica as well as in the Lower Jurassic of Chile, South America, supports the hypothesis that during Jurassic times more than one center of diversification of teleost fishes were operating in far distant regions of the world. Amongst the new material are the oldest marine teleosts (middle–late Callovian to early Kimmeridgian) recovered from Antarctica. They represent the most southern distribution of teleosts during the Jurassic.

ACKNOWLEDGMENTS

Field work in Antarctica of D. Hikuroa was supported by the British Antarctic Survey, and D. Hikuroa gratefully acknowledges funding from the Foundation of Research, Science, and Technology, Te Mata o te Tau, Maniapoto Maori Trust Board, and Te Riutoto Aihe Trust. P. Quilty (UTGD) made available the specimen from his 1965–66 field work. This paper contributes to the BAS science SPARC project. D. Hikuroa also thanks Phil Wickens for his help during fieldwork and BAS Field Operations and Air Unit for field support.

G. Arratia thanks the following colleagues for facilities to study the specimens deposited under their care: C. H. von Daniels (BGHan), the late C. Patterson (BMNH), A. M. Báez (CPBA), L. Grande (FMNH), H. Jahnke (GOE), M. Kölbl-Ebert and G. Viohl (JME), L. Martin (KUVP), A. Paganoni (MCSNB), F. H. Jenkins, Jr. (MCZ), D. Goujet (MNHN), the late D. Frassinetti (MNHN SGO), R. Böttcher (SMNS), and N. Hotton, III (USNM). The manuscript benefited by comments and suggestions by Alberto Cione (La Plata, Argentina), Juergen Kriwet (Stuttgart), Martha Richter (London), and Hans-Peter Schultze (Lawrence, Kansas). Mr. J.-P. Mendau (Berlin) executed the final figures based on the original drawings done by G. Arratia. Mathew Davis (Lawrence, Kansas) helped with the electronic preparation of some of the figures.