Gastralium

Abdominal ribs are skeletal structures in the lower abdomen, which often occurred in theropods and in the extant species only in crocodiles ( Crocodilia ) and find tuatara ( Sphenodon ). Given their location, it is called abdominal ribs also Gastralia (singular Gastric ), Greek γαστήρ gaster = belly. There are remains of a ventral skin bone armor that are not connected to the rest of the skeleton.

The Gastrialalapparat at Prosauropoda lizards and dinosaurs Beck consists of eight to twenty metameric arcuate rows that consist of four or, depending on the adhesion, less bone. A distinction median ( lying towards the center ) and lateral ( lying on the edge ) bone. With median adhesion are only three bones per row, with additional lateral coalescence of just one. The latter is common in the cranial and caudal series situations. The bones of a row and the rows below each other may be hingedly connected, a connection to the rest of the skeleton exists.

Dinosaur Gastralia were described first in 1838 by Eudes - Deslongchamps at Poekilopleuron bucklandii to have recognized without them as dermal bones. Therefore, going back to Osborn description of Gastralia a Tyrannosaurus rex from the year 1906 is often cited as first described. After Osborn's rediscovery Gastralia were soon found in theropod and prosauropods taxa. 1994 Gastralia also described in sauropods ( Apatosaurus ). Recent birds have no more Gastralia, but rather their precursors such as Archaeopteryx or Conficiusornis. Gastralia were also described for the first bird Sinoris santensis. This archaic obtained feature does not seem to affect flight or sitting position to have, but needs to be seen in theropods the closest relatives of birds as an additional indication.

Traditionally, the Gastralia protection and support function of the visceral area are attributed. As adjacent sketches show, the shape of the abdominal breathing could by the Gastralia controlled and therefore have been supported. Today's bird breathing may possibly be attributed to how the article airbag ( bird) is executed.

Gastralia found in only a few extant species, the tuatara and the crocodiles. When the crocodiles from couples curved bone clasps found on the ventral side, eight pairs with genuine crocodiles, seven pairs in alligators. These are not fused medially, but joined by connective tissue.