The skulls are nearly unique in their combination of ontogenetic age and preservational quality and provide us with the first look at the morphology of such important anatomical regions as the rostrum, palate, and braincase at or near the onset of postnatal development in a nonavian paravian coelurosaur. There is thus a disparity between the st.read more read lessĪbstract: The skulls of two perinate paravians from Ukhaa Tolgod, Djadoktha Formation, Mongolia, are described here. Narrowing of the dorsal extremities of the neural spines of the fourth and neighboring vertebrae suggests the ability of this region of the vertebral column to bent upward. Parapophyses slowly migrate upward along the anterior margin of the centrum and leave the centrum at the sixth or seventh dorsal vertebra. There is a sudden change in their morphology behind the seventh vertebra, although otherwise the transition from the cervical to the dorsal vertebrae is very gradual. Cervical ribs of Silesaurus, well preserved in their original disposition, are parallel to the neck and extend backward for a few vertebral lengths. Informative phylogenetic characters pertaining to the furcula occur throughout Theropoda, though care should betake to consider taphonomic effects when describing furcular morphology.read more read lessĪbstract: A recent find of an articulated skeleton of Silesaurus opolensis at its early Late Triassic type locality Krasiejow (Poland), with skull, neck, pectoral girdle, and thorax, supplemented by additional preparation of previously collected articulated specimens, enables complete restoration of the vertebral column and associated skeletal parts. Furculae occur in nearly all major clades of theropods, as shown by new theropod specimens from the Early Cretaceous of China and a close inspection of previously collected specimens. Here we review, or describe for the first time, the furculae in many nonavian theropods. ![]() ![]() Furcular morphology is highly variable in crown-group avians but is rather conserved among nonavian theropods. We review furcula development, function, and morphology, as well as the anatomical terminology applied to it. New specimens from basal theropods suggest that the furcula appeared very early in theropod history. ![]() This is the element which is unique to theropods and is important for understanding the link between birds and other theropods. Abstract: The furcula is a structure formed by the midline fusion of the clavicles.
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