Advanced search
Start date
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

The skull of the Upper Cretaceous snake Dinilysia patagonica Smith-Woodward, 1901, and its phylogenetic position revisited

Full text
Zaher, Hussam [1] ; Agustin Scanferla, Carlos [1, 2]
Total Authors: 2
[1] Univ Sao Paulo, Museu Zool, BR-04263000 Sao Paulo - Brazil
[2] Museo Argentino Ciencias Nat Bernardino Rivadavia, Lab Anat Comparada & Evoluc Vertebrados, RA-1405 Buenos Aires, DF - Argentina
Total Affiliations: 2
Document type: Journal article
Source: ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY; v. 164, n. 1, p. 194-238, JAN 2012.
Web of Science Citations: 38

The cranial anatomy of Dinilysia patagonica, a terrestrial snake from the Upper Cretaceous of Argentina, is redescribed and illustrated, based on high-resolution X-ray computed tomography and better preparations made on previously known specimens, including the holotype. Previously unreported characters reinforce the intriguing mosaic nature of the skull of Dinilysia, with a suite of plesiomorphic and apomorphic characters with respect to extant snakes. Newly recognized plesiomorphies are the absence of the medial vertical flange of the nasal, lateral position of the prefrontal, lizard-like contact between vomer and palatine, floor of the recessus scalae tympani formed by the basioccipital, posterolateral corners of the basisphenoid strongly ventrolaterally projected, and absence of a medial parietal pillar separating the telencephalon and mesencephalon, amongst others. We also reinterpreted the structures forming the otic region of Dinilysia, confirming the presence of a crista circumfenestralis, which represents an important derived ophidian synapomorphy. Both plesiomorphic and apomorphic traits of Dinilysia are treated in detail and illustrated accordingly. Results of a phylogenetic analysis support a basal position of Dinilysia, as the sister-taxon to all extant snakes. The fossil taxa Yurlunggur, Haasiophis, Eupodophis, Pachyrhachis, and Wonambi appear as derived snakes nested within the extant clade Alethinophidia, as stem-taxa to the crown-clade Macrostomata. The hypothesis of a sister-group relationship between Dinilysia and Najash rionegrina, as suggested by some authors, is rejected by the results of our analysis. (AU)

FAPESP's process: 02/13602-4 - Evolution of the southeastern Brazilian reptile fauna from Cretaceous: paleontology, phylogeny and biogeography
Grantee:Hussam El Dine Zaher
Support type: BIOTA-FAPESP Program - Thematic Grants