Memoir Society of Vertebrate Paleontology · 1997 · 210 citations · 0 references
Natural SciencesAnatomyPaleontologyCraniofacial Evolutionary BiologyEvolutionary PaleontologyVertebrate PaleontologyComparative Craniofacial AnatomyComparative OsteologyEvolutionary Developmental PaleontologyFunctional MorphologyPalynomorph MorphologyParanasal Sinus AnatomyArchosaur EvolutionBony ReconstructionFossil Arthropod Soft TissuesFossil Vertebrate AnatomyHominin Craniofacial EvolutionMaxilla MorphologyMaxillofacial MorphologyParanasal Sinus Ostia
The antorbital cavity, a hallmark of Archosauriformes, is a prominent skull opening whose function—whether glandular, muscular, or sinus—is still debated. The study aims to first determine the soft‑tissue function of the antorbital cavity and then assess the biological role of its contents. The authors employ an extant phylogenetic bracket approach to reconstruct the soft‑tissue anatomy of the cavity.
ABSTRACT The most commonly cited apomorphy of Archosauriformes is an opening in the snout known as the antorbital cavity. Despite the ubiquity and prominence of the antorbital cavity, its function and importance in craniofacial evolution have been problematic. Discovering the significance of the antorbital cavity is a two step process: first, establishing the function of the bony cavity (that is, its soft-tissue relations), and second, determining the biological role of the enclosed structure. The first step is the most fundamental, and hence is examined at length. Three hypotheses for the function of the antorbital cavity have been advanced, suggesting that it housed (1) a gland, (2) a muscle, or (3) a paranasal air sinus. Thus, resolution is correctly viewed as a “soft-tissue problem,” and is addressed within the context of the extant phylogenetic bracket (EPB) approach for reconstructing the unpreserved features of fossil organisms. The soft-anatomical relations of the antorbital cavity (or any bony st...