Fig 1.
Geographic overview of Late Cretaceous dinosaur assemblages from the west coast of Laramidia.
The specimen described here was collected from Campanian rocks at Sucia Island (Washington State), but these strata were probably deposited at a more southern latitude, perhaps as far south as the ‘El Gallo’ and La Bocana Roja formations of Baja California, Mexico. See Discussion for overview of specific taxa from each formation. Dinosaur assemblage data were gathered from the following sources: Matanuska Formation [13–15], Northumberland Formation [16, 17], Cedar District Formation [16], Cape Sebastian Sandstone [2, 18], Chico Formation [19, 20], Budden Canyon Formation [21], Moreno Formation [22, 23], Point Loma Formation [24–26], Ladd Formation [2], Rosario Formation [6], ‘El Gallo’ Formation [6, 22, 27–32], La Bocana Roja Formation [33, 34]. Silhouettes modified from images available on Wikimedia Commons.
Table 1.
Linear measurements from selected theropod dinosaur femora.
Fig 2.
The proximal femur of a large theropod dinosaur from Washington State.
Stereopairs of UWBM 95770 in posterior (A), anterior (B) view. Proximal view (C) of UWBM 95770, with arrow indicating anterior direction. Silhouette of complete theropod femur (D) based on the tyrannosaurid Daspletosaurus torosus (TMP 2001.36.01), with corresponding portion of UWBM 95770 highlighted. Abbreviations: 4tr, fourth trochanter; in, matrix infilling of hollow marrow cavity.
Fig 3.
Comparison of theropod dinosaur femora in posterior view.
Illustration of complete theropod femur (A), based on the tyrannosaurid Daspletosaurus torosus (TMP 2001.36.01; total length 987 mm) and (B) the Washington State theropod (UWBM 95770). Abbreviations: 4tr, fourth trochanter; dc, distal condyles; n, femoral neck; tr, area of greater trochanter (but this feature is better seen in anterior view).