INVESTIGADORES
FERNANDEZ Marta Susana
artículos
Título:
Salt glands in a Tithonian metriorhynchid crocodyliform and
Autor/es:
FERNÁNDEZ, M. ; GASPARINI, Z.
Revista:
LETHAIA
Referencias:
Año: 2000 vol. 33 p. 269 - 276
ISSN:
0024-1164
Resumen:
Our knowledge of Mesozoic tetrapods is based mainly on osteological evidence. The
discussion of the evolution of any homeostatic system is highly speculative because direct
non-osteological evidence is uncommon. Here we report an extraordinarily wellpreserved
cast of a pair of lobulated protuberances in the skull of the marine metriorhynchid
crocodiliform Geosaurus from the Tithonian (Jurassic) of Patagonia (Argentina).
These protuberances are interpreted as representing salt glands. Based on their topology,
these glands are identi®ed as the nasals. Optimization of this character on a
phylogenetic tree permits us to infer the ancestral condition for archosaurs. The relationship
between salt gland and diet is also analysed. The presence of hypertrophied
salt glands in the skull of Geosaurus suggests that as early as 140 million years ago,
some Mesozoic marine reptiles had evolved an extra-renal osmoregulatory system. This
achievement was an important clue in the successful colonization of marine environments.
Salt glands preclude the risk of lethal dehydration and allow marine reptiles to
include an important amount of invertebrates in their diet. &Salt glands, metriorhynchids,
osmoregulation, dietGeosaurus from the Tithonian (Jurassic) of Patagonia (Argentina).
These protuberances are interpreted as representing salt glands. Based on their topology,
these glands are identi®ed as the nasals. Optimization of this character on a
phylogenetic tree permits us to infer the ancestral condition for archosaurs. The relationship
between salt gland and diet is also analysed. The presence of hypertrophied
salt glands in the skull of Geosaurus suggests that as early as 140 million years ago,
some Mesozoic marine reptiles had evolved an extra-renal osmoregulatory system. This
achievement was an important clue in the successful colonization of marine environments.
Salt glands preclude the risk of lethal dehydration and allow marine reptiles to
include an important amount of invertebrates in their diet. &Salt glands, metriorhynchids,
osmoregulation, dietGeosaurus suggests that as early as 140 million years ago,
some Mesozoic marine reptiles had evolved an extra-renal osmoregulatory system. This
achievement was an important clue in the successful colonization of marine environments.
Salt glands preclude the risk of lethal dehydration and allow marine reptiles to
include an important amount of invertebrates in their diet. &Salt glands, metriorhynchids,
osmoregulation, diet&Salt glands, metriorhynchids,
osmoregulation, diet