Cranial circulation of the pen-tailed tree shrewPtilocercus lowii and relationships of Scandentia |
| |
Authors: | John R Wible Ulrich Zeller |
| |
Institution: | (1) Department of Anatomical Sciences and Neurobiology, School of Medicine, University of Louisville, 40292 Louisville, Kentucky;(2) Fachbereich Biologie, Institut für Zoologie der Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany |
| |
Abstract: | The major cranial arteries and veins are described for a 30-mm crown-rump length fetus of the pen-tailed tree shrewPtilocercus lowii, and comparisons are made with cranial vessels reported in the tree shrewTupaia and with the vascular pattern reconstructed for primitive eutherians.Ptilocercus shares a number of derived features of the cranial circulation withTupaia, which, therefore, represent synapomorphies of tree shrews (Tupaiidae, Scandentia). Included are (1) the enclosure of the intratympanic portion of the internal carotid artery in a bony canal that is floored proximally and distally by the entotympanic and by the petrosal in between, (2) the enclosure of the intratympanic portion of the stapedial artery by the petrosal in a canal on the promontorium and within the epitympanic crest beneath the tympanic roof, (3) the absence of an exit for the arteria diploëtica magna, (4) an alisphenoid canal, (5) a maxillary artery that passes medial to the mandibular nerve beneath foramen ovale, and (6) a laryngeopharyngeal artery. Some of these derived features, however, are also found in certain other eutherians (e.g., numbers 2, 3, and 6 in Euprimates) and, therefore, may be used in future studies to assess the higher-level affinities of Scandentia. |
| |
Keywords: | cranial circulation Ptilocercus Tupaia Scandentia |
本文献已被 SpringerLink 等数据库收录! |
|