Abstract
Furculae have been identified in many dinosaurs and are synapomorphic in some clades (e.g., dromaeosaurids). All coelophysid dinosaurs exceptCoelophysis bauri have been shown to possess furculae. To date, the oldest well-documented furculae have been those of the Early Jurassic coelophysids,Coelophysis kayentakatae andCoelophysis rhodesiensis. The confirmation of furculae in Apachean-agedC. bauri further documents appearance of these elements in the Late Triassic and shows that furculae are synapomorphic in the Coelophysidae. A total of five furculae have been found in New Mexico Museum of Natural History’s (NMMNH) Ghost Ranch, New Mexico Whitaker Quarry block C-8-82. We describe three furculae in articulated juvenile skeletons; two that are missing fragments but are nearly complete, and one apparently complete, a small fragment of a furcula associated with an adultC. bauri, and one complete but isolated furcula. We access the morphology and allometry of the scapulocoracoid and furcula and show that they grow, at least in juveniles, in isometry with the humerus. The furcula ofC. bauri has a widely opened U shape that subtends an angle of ∼ 120°. All the furculae have groove-like epicleidial facets at the distal ends of the rami and some possess a small centrally located hypocleideal process. We reconstruct the complete Shoulder girdle ofC. bauri with proper spacing and angles between the elements and find that the coracoids are very close together under the center of the furcula.
Kurzfassung
Furculae wurden in vielen Dinosauriern gefunden und sind in einigen Gruppen synapomorph (z.B. Dromaeosauridae). Furculae wurden in allen Coelophysiden nachgewiesen, mit der Ausnahme vonCoelophysis bauri. Die ältesten gut dokumentierten Furculae bei Theropoden waren bisher jene der unterjurassischen CoelophysidenCoelophysis kayentakatae undCoelophysis rhodesiensis. Die Bestätigung der Präsenz von Furculae inCoelophysis bauri, mit einem Apachium-Alter, beweist weiter den Ursprung dieses Elementes in der späten Trias und zeigt, dass Furculae für Coelophysiden synapomorph sind. Insgesamt wurden fünf Furculae in dem Block C-8-82 aus dem Ghost Ranch, New York Whitaker Quarry im New Mexico Museum of Natural History (NMMNH) gefunden. Wir beschreiben drei Furculae von artikulierten, juvenilen Exemplaren, von denen zwei fast vollständig und eine scheinbar vollständig ist, eine fragmentarische Furcula, die mit einem adulten Exemplar vonCoelophysis bauri assoziiert ist und eine vollständige, aber isolierte Furcula. Wir analysieren die Morphologie und Allometrie des Scapulocoracoids und der Furcula und zeigen, dass sie, zumindest in Jungtieren, in Bezug auf den Humerus isometrisch wachsen. Die Furcula vonC. bauri ist breit U-förmig, mit einem Winkel von ungefähr 120° zwischen den Ästen. Alle Furculae haben kleine, grubenförmige Epicleithral-Facetten an den distalen Enden der Äste und einige weisen kleine, zentral gelegene Hypocleithral-Fortsätze auf. Wir rekonstruieren den gesamten Schultergürtel vonC. bauri, mit den exakten Abständen und Winkeln zwischen den Elementen und finden, dass die Coracoide unter der Spitze der Furcula sehr eng zusammen lagen.
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Rinehart, L.F., Lucas, S.G. & Hunt, A.P. Furculae in the Late Triassic theropod dinosaurCoelophysis bauri . Paläontol Z 81, 174–180 (2007). https://doi.org/10.1007/BF02988391
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DOI: https://doi.org/10.1007/BF02988391