USE OF THE EXTANT PHYLOGENETIC BRACKET (EPB) METHOD FOR MUSCLE RECONSTRUCTION IN THE NECK OF PTEROSAURS

The Extant Phylogenetic Bracket (EPB) method defines criteria for inferences of soft tissue characteristics of extinct species from the anatomy of extant ones that are phylogenetically related to them. Here, through dissections of extant archosaurs we aimed to discuss the reconstruction of the neck muscles of pterosaurs. The dissections were performed only on adult individuals belonging to the clades Crocodylia (_Caiman latirostris_) and Neornithes (_Ardea alba_, _Calonectris diomedea_, _Cariama cristata_, _Phalacrocorax brasilianus_, and _Sterna hirundo_). The length of the intervertebral space composed of cartilage ranges from 1 to 2 mm. We observed that the main difference between the cervical musculature of these Crocodylia and Neornithes is established by the shorter cervical vertebral column presented by alligators, which corresponds to a craniocaudal compaction of the neck musculature, including muscles inserted in the pectoral girdle, as the muscle _scapulahumeralis cranialis_, that reaches the middle portion of neck in _Caiman latirostris_. The well developed vertebral laminae in the middle portion of the neck in _Caiman latirostris_ serve as anchor points for robust muscles, differing from the Neornithes. The size variation presented between the centra and neural arch along the vertebrae on the segments of the neck of birds is also observed in the superficial musculature, in which the muscles _longus colli dorsalis_ are more robust in the I and III segments of the neck while the _longus colli ventralis_ are robust in the II segment. Variations of the musculature between the observed bird species are rare, such as the absence of the muscle _biventer cervicis_ in _Sterna hirundo_. The similarity between muscular scars, long centrum with prominent hypapophysis and neural arch with little developed transverse processes seen in the cervical vertebrae of pterosaurs and extant birds indicate that the disposition of the superficial and deep musculature of their necks are also equivalent. However, the similarity between the pronounced neural spines along the neck and the same number of cervical vertebrae between _Caiman latirostris_ and pterosaurs also reliably evidences the probable sites of muscular insertions and origins along the neck. [CAPES].