Résumé
This study, based on previously undescribed crocodile remains from the
Early Miocene of the Bugti Hills (Balochistan, Pakistan), reveals the
existence of at least three distinct species. It confirms the validity of
the species initially identified as "Gavialis" pachyrhynchus,
establishing it as the sister taxon to the massive Miocene crocodile
Rhamphosuchus crassidens. Consequently, it is reclassified as
Rhamphosuchus pachyrhynchus. Additionally, "Gharialis"
curvirostris is now acknowledged as a valid species under the new genus
name Pseudogavialis, closely related to Gavialis. Another set of remains
represents a third species, although the poor preservation hinders precise
identification. The phylogenetic relationships between Tomistoma and
Gavialis are one of the most debated issues in crocodylian phylogeny.
Molecular analyses suggest a sister-taxa relationship dating back to the
Early Miocene, while morphological analyses place Gavialis at the base of
the tree, diverging from thoracosaurs, with a Gavialoidea/Crocodyloidea
split in the Cretaceous. The inclusion of newly described species in
phylogenetic analyses yields variable outcomes, highlighting the
sensitivity of results to the species considered. The insertion of
Portugalosuchus azenhae, found as a thoracosaurine, aligns with
traditional morphological findings, while the inclusion of Indo-Pakistani
species of Rhamphosuchus supports the molecular hypothesis. Nevertheless,
when the molecular result is found, a large number of morphologic
gavialoids and thoracosaurines make the result strongly stratigraphically
incongruent. The inclusion of fossil species in the phylogenetic analyses
significantly impacts the understanding of crocodylian relationships. Even
when molecular results align with morphological data, the persistent
stratigraphic incongruence does not resolve the Gavialis-Tomistoma
dilemma.