Do crocodiles have gastralia?
Gastralia (singular gastralium) are dermal bones found in the ventral body wall of modern crocodilians and tuatara, and many prehistoric tetrapods.
What animals have gastralia?
Gastralia are also present in a variety of extinct animals, including theropod and prosauropod dinosaurs, pterosaurs, plesiosaurs, and champsosaurs. In dinosaurs, the elements articulate with each other in a sort of zig-zag along the midline and may have aided in respiration.
What are gastralia in lizards?
Gastralia are bones protecting the ventral area of a vertebrate. They are found in some living and fossil reptiles.
Is plesiosaur extinct?
Finally extinct Plesiosaurs thrived during the Jurassic and Cretaceous. Some evolved into the short-necked, large-headed pliosaurs, such as the enormous Predator X. They died out 66 million years ago, along with the dinosaurs.
Do crocodiles have a sternum?
The sternum is absent in the turtles and in the snakes; in the crocodiles it is a wide plate joined by the coracoid processes and by two pairs of ribs.
Does crocodile have ribs?
You have seven true ribs attached to the breast bone (sternum), three false ribs that are attached to the spine and combine at the bottom of the seventh rib, and two floating ribs.
Do all reptiles have osteoderms?
Osteoderms are found in many groups of extant and extinct reptiles and amphibians, including lizards, crocodilians, frogs, temnospondyls (extinct amphibians), various groups of dinosaurs (most notably ankylosaurs and stegosaurians), phytosaurs, aetosaurs, placodonts, and hupehsuchians (marine reptiles with possible …
Do sauropods have osteoderms?
Osteoderms are bones embedded within the dermis, and are common to select members of most major tetrapod lineages. The largest known animals that bear osteoderms are members of Titanosauria, a diverse clade of sauropod dinosaurs.
What is the function of the gastralium in a crocodile?
Gastralia (singular gastralium) are dermal bones found in the ventral body wall of modern crocodilian and Sphenodon species. They are found between the sternum and pelvis, and do not articulate with the vertebrae. In these reptiles, gastralia provide support for the abdomen and attachment sites for abdominal muscles.
What are Plesiosaurus’ gastralia?
These gastralia are much smaller rib-like formations that have a bone on the midline that is flanked on each side by three other bones. Plesiosaurus’finnage, paddles, or limbs consisted of five digits on the hand paddle, six bones in the wrist, distinctive curvature to the humerus and a strong pillar-like radius.
What type of animal is plesiosaur?
Plesiosaurs are a group of secondarily aquatic carnivorous reptiles belonging to the clade Sauropterygia within the diapsid clade Euryapsida (Tayor, 1989; Caldwell, 1997). The Plesiosauria has retained phylogenetic validity for well over 150 years, since the formal identification of the clade by de Blainville (1835).
Was Plesiosaurus a crocodile or ichthyosaur?
What the naturalists did not realize was that Plesiosaurus was not an intermediate form between crocodiles and ichthyosaurs, after all, but a unique and starkly different sort of marine reptile. Missing bones were what caused them to miscast their mosnter.