Zemes un vides zinātnes Earth and Environment Sciences - Latvijas ...

ACTA UNIVERSITATIS LATVIENSIS, 2004, Vol. 679, pp. 79-98
A new tetrapod Jakubsonia livnensis from the
Early Famennian (Devonian) of Russia and
palaeoecological remarks on the Late Devonian
tetrapod habitats
OLEG A. LEBEDEV
Oleg A. Lebedev, Palaeontological Institute of the Russian Academy of Sciences, 123
Profsoyuznaya St., Moscow 117997, Russia; olebed@paleo.ru
Skeletal remains of the earliest tetrapod Jakubsonia livnensis gen. et sp. nov. are described from
the Lower Famennian, Upper Devonian of the Gornostayevka quarry (SW of the Livny Town,
Oryol Region, Russia). A part of the skull roof, incomplete angular, the right cleithrum with
scapulocoracoid and partial femur are described. The new genus demonstrates characters in the
structure of the interorbital region and the cleithrum suggesting similarity to the Ventastega
Ahlberg, Lukševics and Lebedev, 1994.
An analysis of early tetrapod sites indicates that these animals dwelled within a wide range of
aquatic environments. The antiarch genus Remigolepis played an important role in Famennian
tetrapod communities. The presence of more than one tetrapod in the communities indicates
many more diverse tetrapod trophic adaptations than previously considered.
Key words: tetrapods, Russia, Oryol region, Devonian, Famennian, palaeoecology,
Jakubsonia.
Introduction
Studies of Late Devonian tetrapods became especially intensive during the last decade
of the 20th century. Apart from Ichthyostega Säve-Söderbergh, 1932 and Acanthostega
Jarvik, 1952, new taxa from most continents of the world, of both Laurussian and
Gondwanan origin, have recently been described. Most of these tetrapods (Metaxygnathus
Campbell and Bell, 1977, from Australia, Tulerpeton Lebedev, 1984 from Russia,
Hynerpeton Daeschler, Shubin, Thomson and Amaral, 1994 and Densignathus Daeschler,
2000 from Pennsylvania (U.S.A.), Ventastega Ahlberg, Lukševics and Lebedev, 1994
from Latvia, Sinostega Zhu, Ahlberg, Zhao and Jia, 2002 from China and an ichthyostegid
tetrapod from Belgium) (Campbell and Bell 1977; Lebedev 1984; Lebedev and Clack
1993; Daeschler et al. 1994; Lebedev and Coates 1996; Ahlberg, Lukševics and Lebedev
1994; Daeschler 2000; Zhu et al. 2002; Lukševics, Ahlberg and Clack 2003; Clement et
al. 2004) originate from the upper and middle Famennian deposits. Only Elginerpeton
pancheni Ahlberg, 1995 is known from the upper Frasnian of Scotland (Ahlberg 1995,
1998). For that reason, each new find of tetrapod material in deposits older than middle
Famennian make a contribution of special interest to our knowledge in this field of
vertebrate palaeontology.
The first finds of vertebrates from the rich fossil vertebrate locality Gornostayevka
quarry (sometimes previously called the Livny quarry) situated to the SW of the Livny