28
1.2.3.2 Class Reptilia (Reptiles)
This class includes cold-blooded (ectothermic) animals, which use lungs to breathe,
and have tough featherless or hairless skin. Reptiles cannot survive in extremely
cold climates because they cannot regulate their internal body temperature. The evolution of marine reptiles started about 250 Ma in the Early Triassic. These vertebrates
dominated Mesozoic seas until their demise by the end of the Cretaceous, 65 Ma
(see for review McGowan and Motani 2003 ; Motani 2009 ; Benson et al. 2010 ).
Typical representatives of marine reptiles in the Triassic are—the mollusk eating,
armored placodonts as well as pachypleurosaurs and nothosaurs. Both related to
the long-necked fi sh-eating eosauropterygians (Rieppel 1995 ). Also serpentine
thalattosaurs, and the streamlined ichthyosaurs (Motani 2005 )—are examples of
faunal recovery in the oceans following the devastation of the end Permian mass
extinction. However, most of these marine reptile species disappeared in the Late
Triassic. During Jurassic period, predators like plesiosaurs, marine crocodilians and
ichthyosaurs dominated in the oceans (Thorne et al. 2011 ).
The fi rst tetrapods with a fi sh-shaped body profi le were parvipelvian ichthyosaurs.
These animals are characteristic examples of the secondary adaptation of reptiles
to marine life. According to Bernard et al. ( 2010 ), “ichthyosaurs evolved from
basal neodiapsid reptiles, with the most obvious aquatic adaptations: a dolphin- like
streamlined body without a neck, paddles, and a fi sh-like tail,” (Bernard et al. 2010 ).
They possess morphological features of cruising forms, similar to a living tuna. Several
species were deep divers. The cancellous bone is the common character observed
in genera such as Caypullisaurus, Stenopterygius, Temnodontosaurus, and Ichthyosaurus. Because of this feature, the fi sh-shaped ichthyosaurs are suggested as fast
and far cruisers (Talevi and Fernández 2012 ). “The evolution of ‘thunniform’ body
Fig. 1.7 The crab-eating frog ( Fejervarya cancrivora) is considered to possess the highest salinity
tolerance among amphibians. Size (snout to vent): Female 8 cm, Male 7 cm (Image courtesy of
Nick Baker, www.ecologyasia.com )
1 Introduction
1.2.3.2 Class Reptilia (Reptiles)
This class includes cold-blooded (ectothermic) animals, which use lungs to breathe,
and have tough featherless or hairless skin. Reptiles cannot survive in extremely
cold climates because they cannot regulate their internal body temperature. The evolution of marine reptiles started about 250 Ma in the Early Triassic. These vertebrates
dominated Mesozoic seas until their demise by the end of the Cretaceous, 65 Ma
(see for review McGowan and Motani 2003 ; Motani 2009 ; Benson et al. 2010 ).
Typical representatives of marine reptiles in the Triassic are—the mollusk eating,
armored placodonts as well as pachypleurosaurs and nothosaurs. Both related to
the long-necked fi sh-eating eosauropterygians (Rieppel 1995 ). Also serpentine
thalattosaurs, and the streamlined ichthyosaurs (Motani 2005 )—are examples of
faunal recovery in the oceans following the devastation of the end Permian mass
extinction. However, most of these marine reptile species disappeared in the Late
Triassic. During Jurassic period, predators like plesiosaurs, marine crocodilians and
ichthyosaurs dominated in the oceans (Thorne et al. 2011 ).
The fi rst tetrapods with a fi sh-shaped body profi le were parvipelvian ichthyosaurs.
These animals are characteristic examples of the secondary adaptation of reptiles
to marine life. According to Bernard et al. ( 2010 ), “ichthyosaurs evolved from
basal neodiapsid reptiles, with the most obvious aquatic adaptations: a dolphin- like
streamlined body without a neck, paddles, and a fi sh-like tail,” (Bernard et al. 2010 ).
They possess morphological features of cruising forms, similar to a living tuna. Several
species were deep divers. The cancellous bone is the common character observed
in genera such as Caypullisaurus, Stenopterygius, Temnodontosaurus, and Ichthyosaurus. Because of this feature, the fi sh-shaped ichthyosaurs are suggested as fast
and far cruisers (Talevi and Fernández 2012 ). “The evolution of ‘thunniform’ body
Fig. 1.7 The crab-eating frog ( Fejervarya cancrivora) is considered to possess the highest salinity
tolerance among amphibians. Size (snout to vent): Female 8 cm, Male 7 cm (Image courtesy of
Nick Baker, www.ecologyasia.com )
1 Introduction