Producción CyT
Libro de Resúmes de las 37 JAPV - ENDOCRANIAL ANATOMY OF NOTOSUCHUS TERRESTRIS (CROCODYLIFORMES, MESOEUCROCODYLIA) FROM THE CRETACEOUS OF PATAGONIA: PALEOBIOLOGICAL IMPLICATIONS
Congreso
Fecha:
2024Editorial y Lugar de Edición:
CorreintesResumen *
Notosuchus terrestris is an iconic taxon in the phylogeny and paleobiology of Crocodyliformes. Few studies were carried out on its cranial and post-cranial anatomy, while studies on its endocranial anatomy and paleoneurology still needed to be addressed. This contribution explores the endocranial anatomy and paleoneurology of this taxon, and its paleobiological implications in Crocodyliformes. Different specimens housed in paleontological collections of the Museo Argentino de Ciencias Naturales Bernardino Rivadavia (MACN), Museo de Ciencias Naturales de La Plata (MLP), and Museo Provincial Carlos Ameghino of Cipolletti (MPCA) were reviewed. Some specimens (MLP 64-IV-16-5, MLP 64-IV-16-30, MACN-Pv-RN-1037, MPCA-Pv 237) were X-Ray CT scanned. The segmentations of the endocranial cavities were carried out with the Materalise Mimics software. The brain endocast of Notosuchus presents a morphology similar to basal Crocodylomorpha being elongated anteroposteriorly and slightly sigmoidal in lateral view, with angles between the forebrain, midbrain and hindbrain of ~175° and ~155°, respectively. In dorsal view, the olfactory bulbs are developed laterally as in other notosuchians (Baurusuchus, Simosuchus, Hamadasuchus) but not in Crocodylia. The olfactory tract has a marked ventral inclination (~151° with respect to the cerebral hemispheres). The cerebral hemispheres are not expanded laterally as observed in peirosaurids, uruguaysuchids, Simosuchus and Crocodylia. The pituitary is very developed and elongated anteroposteriorly. The midbrain region is also anteroposteriorly elongated. The hindbrain is tall dorsoventrally and does not have prominent cerebellar flocculi like other cocodrylomorphs. The cranial nerves have the same morphology and distribution than extant Crocodylia, except for the following differences: markedly anteroposteriorly elongated ophthalmic branch of the trigeminal nerve (CN V1), small and lateralized trigeminal ganglion, and craniocervical trunk (CNs IX-X-XI) without ramus communicans directed dorsolaterally. Regarding the vasculature, the longitudinal venous sinus between the otic capsules is transversely wide, as in other notosuchians (Araripesuchus, Simosuchus, Baurusuchus) but lacks the marked dorsal protrusion seen in most crocodyliforms. The inner ear is partially reconstructed and presents the same subtriangular morphology with the anterior semicircular canal slightly larger observed in other Crocodyliformes. Notosuchus (like other notosuchians such as Simosuchus, Campinasuchus, and Sebecus), has a paratympanic sinus system with diverticula largely invading dermal and endocondral bones (e.g. parietal, squamosal, quadrate, pterygoid, prootic), greater than that observed in Crocodylia. Many of these characteristics would be related to terrestrial habits (e.g. size of olfactory bulbs and trigeminal ganglion, cranial pneumaticity) inferred for Notosuchus terrestris, in contrast to other cocodryliforms with aquatic or semiaquatic habits. Información suministrada por el agente en SIGEVAPalabras Clave
PALEONEUROLOGYNOTOSUCHIA