Lyraetípusú

Lyraetípusú is a hypothetical genus of extinct cephalopods, proposed to have existed during the Late Cretaceous period. The name Lyraetípusú is derived from ancient Greek words, referencing the distinctive lyre-like shape of its shell. The genus is characterized by a coiled shell, reminiscent of modern nautiloids, but with a more pronounced dorsoventral flattening. The whorls are tightly wound, with the initial whorls partially or completely embracing the subsequent ones. The most striking feature, however, is the prominent median keel that runs along the ventral side of each whorl, creating the characteristic lyre-like profile when viewed from the side.

Fossil evidence for Lyraetípusú is scarce and primarily consists of internal molds and fragmented shells. These remains suggest a nektonic lifestyle, with the organism likely inhabiting shallow to moderately deep marine environments. The shell morphology indicates a potential adaptation for stability and efficient swimming, though the exact ecological niche remains speculative. Due to the limited fossil record, detailed information about Lyraetípusú's internal anatomy, diet, or reproductive strategies is largely unknown. The genus is thought to be related to other Late Cretaceous ammonites, but its precise phylogenetic position within the Cephalopoda is still under debate among paleontologists. Further discoveries are needed to fully understand the evolutionary history and significance of Lyraetípusú.