Functional morphology of the hindlimb of fossilized pygmy hippopotamus from Ayia Napa (Cyprus).

We studied the functional morphology of the postcranial skeleton of the endemic hippopotamus Phanourios minor, derived from the Upper Pleistocene site of Ayia Napa. The deposit, which consists of a hard limestone substrate on which the species moved, has yielded a great abundance of hippopotamus material, making the Ayia Napa locality one of the most important paleontological sites in Cyprus. The immigration of the large-sized mainland Hippopotamus to Cyprus led to the emergence of a new insular species with its main characteristic being the extremely reduced body size. In this study, all the hindlimb elements of the Cypriot hippo are described in detail and compared with those of the modern species, with the extant Hippopotamus amphibius being considered similar to the possible ancestor of P. minor. In some cases, the morphological comparison is reinforced using bones of other extinct insular and mainland hippos. Additionally, we provided a functional analysis of the hindlimb joints, suggesting specific locomotor habits for the species. The anatomical examination reveals that the elements in P. minor are robust with marked muscular insertion areas resembling those found in Hippopotamus. However, there are also similarities with Choeropsis liberiensis in certain morphofunctional traits. P. minor adapted to slow but powerful locomotion with remarkable stabilization, particularly in the zeugopodium and the autopodium. The knee was less mobile in the craniocaudal direction compared with that in recent hippos, while the abduction-adduction movements of the thigh were advanced. The pes presented good mobility in the sagittal plane and limitation in transversal movements. Thus, P. minor displayed modifications to its limbs, influenced by the mountainous island environment and the body size reduction, resulting in specialized locomotion, which was different from that of extant hippopotamuses.

Morphofunctional examination of the carpal bones of pygmy hippopotamus from Ayia Napa, Cyprus.

This study provides a complete morphological description and functional analysis of the carpal bones of the endemic pygmy hippopotamus Phanourios minor, derived from the Upper Pleistocene site of Ayia Napa. From this deposit, numerous skeletal remains of this fossil hippo have been collected, making the locality one of the richest in Cyprus. The carpal bones were compared with those of extant hippopotamuses, to determine the changes that occurred in the fossil hippo. Examination of the elements showed that Phanourios presented some important features that were common among the endemic fossil ungulates of the Mediterranean islands. The carpal bones display a proximal-distal compression due to shortening of the distal part of the leg, due to the new ecological island conditions. However, they are robust with rough areas for strong muscular and ligament insertions, providing stability to the carpal joints, and low speed movement to the animal. The great flexor capabilities, and the limitation in ulnar deviation of the carpus, indicate that P. minor had increased agility in the sagittal plane and restricted transverse movements, while the suggestion of a more unguligrade stance for the species is ambiguous. Thus, the endemic Cypriot hippos developed specialized locomotion, suitable for walking on the rugged terrain of Cyprus, which seems to be different from that of its extant counterparts.

Molecular phylogeny of the extinct pleistocene dwarf elephant Palaeoloxodon antiquus falconeri from Tilos Island, Dodekanisa, Greece.

A partial sequence of cytochrome b (228 bp) gene of mitochondrial DNA was successfully determined from rib bones of the dwarf elephant Palaeoloxodon antiquus falconeri BUSK, which were excavated from Charkadio cave of the island of Tilos, Dodekanisa, Greece. This is the first report of DNA sequence of a dwarf elephant. The sequences were used to examine the phylogenetic relationships among Elephantidae. Phylogenetic trees reconstructed by the neighbor-joining and maximum parsimony methods provided identical topologies. The results support the "Palaeoloxodon-Elephas" clade, which is consistent with previous morphological reports according to which Palaeoloxodon is more closely related to Elephas than to Loxodonta or Mammuthus.