Athena Review Image Archive ™
Limnoscelis skleleton
Skeleton of Limnoscelis (after Benton 2005)
Limnoscelis was a large carnivorous amphibian in the order of reptilomorphs, which were ancestral to reptiles. The type species Limnoscelis paludis was
found by Samuel Williston in 1911 in El Cobre Canyon in the
Cutler Formation of New Mexico. Dating from the Late Pennsylvanian and
Early Permian periods (310-280 mya), it belongs to the class Amphibia,
the order reptilomorpha, and the suborder Diadectamorph, more
developed reptilomorph amphibians including the type species Diadectes, Limnoscelis, and Tseajaia.
These
show a mixture of reptilian and amphibians traits, combining a robust,
reptile-like skeleton with a more primitive, thick-boned skull
resembling that of a Seymourian amphibian. Heavy vertebrae and ribs,
massive limb girdles and short, robust limbs indicate that
Diadectamorphs were fully terrestrial animals. Diadectes was one of the very earliest herbivorous tetrapods. Its teeth show advanced specializations for herbivorous diet.
Limnoscelis was
a relatively large reptilomorph, about 1.5 - 2 meters in length. Its
pectoral and pelvic bones were large and robust, showing a
well-developed mode of walking. Other reptilian traits include a larger
braincase structure, reptilian jaw muscles, and expanded neural
arches.Its
arms and hands showed the primitive tetrapod traits of humerus, radius,
ulna, and five digits. The digits lacked claws. The ankle bones,
meanwhile, were fused as in other reptile-like amphibians. This would
not allow them to use their feet actively in
traction.
The skull of Limnoscelis had a deep premaxilla with robust premaxillary fangs. The maxilla or upper jaw was deeper, with short teeth which indicate a carnivorous diet. The eye orbit was relatively smaller than in the related taxa Oedaleops, but in most other respects, the skulls were similar.
References:
Benton, M.J. 2005. Vertebrate Paleontology. Blackwell Publishers.
Romer, A.S. 1966. Vertebrate Paleontology. University of Chicago Press.
Williston, S.W. 1911. A new family of reptiles from the Permian of New Mexico. American Journal of Science, Series 4, 31:378-398.
Copyright © 1996-2020 Rust Family Foundation (All Rights Reserved).