Temporal Range: Late Triassic (235-223.4 Mya)
Length: 1 metre
– Discovery: Henodus is the only known member of the henodontid family of placodonts. Fossils of Henodus have been discovered in Germany and the species was named by Friedrich von Huene in 1936.
– Description: Henodus is the placodont which most resembles a modern day turtle in terms of looks. It had a single piece carapace which covered the entire body and stretched out almost covering the limbs entirely. This carapace was extremely tough; made up of a fusion of a large number of interlocking bony scutes, which were then covered by a layer of horn. The carapace of Henodus was fused to its spine, and was almost as wide as it was long. This oversized shell would have acted as the ultimate form of protection from marine predators, and it is likely that most Triassic predators would not have been able to fit the shell of a fully grown Henodus between their jaws. This shell however would have been a great hindrance when Henodus was on land, and coupled with its extremely weak limbs, it is thought that Henodus would have spent very little time on land.
Henodus differed from other placodonts in that the mouth was broad and squared off instead of pointed. Researchers believed Henodus would have used its broad mouth to shovel through sediment to find buried shellfish, whilst other placodonts with pointed mouths were better suited to plucking shellfish from between rocks. Henodus is the only placodont thus far to be found in non-marine deposits, suggesting it may have lived in brackish or freshwater lagoons and this unique lifestyle may explain its different feeding style.
(Restoration Source: http://kahless28.deviantart.com/art/Henodus-144382016)