Post by Deleted on Dec 7, 2022 22:16:37 GMT 5
Rhizodus (root tooth) is an extinct genus of rhizodont, a branch of the Sarcopterygii, the bony vertebrate clade that also includes tetrapods. It was of enormous size, reaching 6–7 metres (20–23 ft) in length. The most notable characteristics of Rhizodus, when compared to other giant lobe-fins such as Barameda, were the two giant 22 cm fangs located near the front of its jaws, followed by other teeth scaling downwards in size. Rhizodus was a giant apex predator that resided in freshwater lakes, river systems and large swamps in the entire Carboniferous period, feeding on small to medium-sized amphibians (ranging from 30 cm to 600 cm in size), using its teeth to kill prey and rip it into digestible sizes, rather than swallowing prey whole like other, smaller-toothed sarcopterygii. Fossil skin imprints show that Rhizodus had large, plate-like scales, similar to those found on modern day arapaimas. Rhizodus' diet includes medium sized fish and temnospondyls. It has been proposed that Rhizodus may have lunged at terrestrial, shorebound prey, just like a modern day crocodile.
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Mastodonsaurus (meaning "breast tooth lizard") is an extinct genus of temnospondyl amphibian from the Middle Triassic. It belongs to a Triassic group of temnospondyls called Capitosauria, characterized by their large body size and presumably aquatic lifestyles. Like those of many other capitosaurs, the head of Mastodonsaurus was triangular, reaching about 1.25 metres (4.1 ft) in the largest specimens. The total length of the largest individuals is about 4 to 6 metres (13 to 20 ft). The large, oval eye sockets are midway along the skull. The jaws are lined with conical teeth. Two large tusks project up from the end of the lower jaw, fitting through openings on the palate and emerging out from the top of the skull when the jaw is closed. The body of Mastodonsaurus is relatively small in proportion to the large head, and the tail is relatively short. The greatly reduced limb bones have joints that are poorly developed. The marked reduction of the limbs and grooves on the head called sensory sulci show that Mastodonsaurus was an aquatic animal that rarely left water. Mastodonsaurus may have been completely unable to leave the water, as large quantities of bones have been found that suggest individuals died en masse when pools dried up during times of drought. It inhabited swampy pools and lived mainly on fish, whose remains have been found in its fossilized coprolites. It probably also ate land-living animals, such as small archosaurs. The fossils of some smaller temnospondyls bear tooth marks made by Mastodonsaurus-like animals. Mastodonsaurus was once thought to be responsible for the footprints found in Triassic sandstones and described as Chirotherium, but more recent research had found that the tracks belong to crocodile-like pseudosuchian reptiles.
