An avian quadrate from the Late Cretaceous Lance Formation of Wyoming

Citation
A. Elzanowski et al., An avian quadrate from the Late Cretaceous Lance Formation of Wyoming, J VERTEBR P, 20(4), 2000, pp. 712-719
Citations number
29
Categorie Soggetti
Earth Sciences
Journal title
JOURNAL OF VERTEBRATE PALEONTOLOGY
ISSN journal
02724634 → ACNP
Volume
20
Issue
4
Year of publication
2000
Pages
712 - 719
Database
ISI
SICI code
0272-4634(200012)20:4<712:AAQFTL>2.0.ZU;2-3
Abstract
Based on an extensive survey of quadrate morphology in extant and fossil bi rds, a complete quadrate from the Maastrichrian Lance Formation has been as signed to a new genus of most probably odontognathous birds. The quadrate s hares with that of the Odontognathae a rare configuration of the mandibular condyles and primitive avian traits, and with the Hesperornithidae a uniqu e pterygoid articulation and a poorly defined (if any) division of the head . However. the quadrate differs from that of the Hesperornithidae by a hing e-like temporal articulation, a small size of the orbital process, a well-m arked attachment for the medial (deep) layers of the protractor pterygoidei et quadrati muscle, and several other details. These differences, as well as the relatively small size of about 1.5-2.0 kg, suggest a feeding special ization different from that of Hesperornithidae.