Fig 1.
Geographic and stratigraphic distribution of Edmontosaurus regalis in Alberta (modified from [8, 17]).
A, map of southern Alberta; the grey rectangle highlights the central region of the Red Deer River valley, where E. regalis specimens were collected. B, magnified map of the grey rectangular region in Fig 1A, showing the localities of the holotype (CMN 2288) and paratype (CMN 2289) of E. regalis. C, stratigraphic subdivision of the Horseshoe Canyon Formation, with the stratigraphic range of E. regalis.
Fig 2.
Reconstruction of Edmontosaurus regalis mainly based on CMN 2288, CMN 2289, CMN 8399, and UALVP 53722 (modified from Campione and Evans [8]).
Fig 3.
Incomplete cranium of Edmontosaurus regalis (CMN 2288) in left lateral (A, B) and dorsal (C, D) views; photographs (left) and line drawings (right).
Fig 4.
Close-ups of the cranium of Edmontosaurus regalis (CMN 2288).
A, left laterodorsal view of the snout. B, anterodorsal view of the snout. C, left laterodorsal view of the skull roof. D, left anterolateral view of the posterior half of the skull. E, posterior view of the skull. F, left anterolateral view of the neurocranium through the orbit. The prominent postorbital pocket is indicated by a red arrow.
Fig 5.
Left and right maxillae of Edmontosaurus regalis (CMN 2289) in lateral (A, B), medial (C, D), dorsal (E, F), and ventral (G, H) views.
Fig 6.
Articulated left maxilla, palatine and ectopterygoid, and articulated right maxilla, palatine and ectopterygoid of Edmontosaurus regalis (CMN 2289) in lateral (A, B) and medial (C, D) views.
Fig 7.
Articulated left nasal, prefrontal, lacrimal and frontal, and articulated right nasal, prefrontal, lacrimal and frontal of Edmontosaurus regalis (CMN 2289) in lateral (A, B), medial (C, D), dorsal (E, F), ventral (G, H), and posterior (I, J) views.
Fig 8.
Left and right jugals of Edmontosaurus regalis (CMN 2289) in lateral (A, B) and medial (C, D) views. Close-ups of the jugal anterior process of CMN 2288 in lateral (E) and posterolateral (F) views. Left and right quadratojugals of Edmontosaurus regalis (CMN 2289) in lateral (G, H) and medial (I, J) views. The sharp posterolateral projection of the jugal along the orbital margin is indicated by an arrow.
Fig 9.
Left quadrate of Edmontosaurus regalis (CMN 2289) in lateral (A), medial (B), anterior (C), and posterior (D) views.
Fig 10.
Partial, articulated skull roof and neurocranium of Edmontosaurus regalis (CMN 2289) in dorsal (A, B) and ventral (C, D) views; photographs (left) and line drawings (right).
Fig 11.
Partial, articulated skull roof and neurocranium of Edmontosaurus regalis (CMN 2289) in left lateral (A, B) and right lateral (C, D) views; photographs (left) and line drawings (right).
Fig 12.
Partial, articulated skull roof and neurocranium of Edmontosaurus regalis (CMN 2289) in anterior (A, B) and posterior (C, D) views; photographs (left) and line drawings (right). The well-developed postorbital pocket is indicated by an arrow.
Fig 13.
Left and right ectopterygoids of Edmontosaurus regalis (CMN 2289) in lateral (A, B) and medial (C, D) views. Left and right palatines of Edmontosaurus regalis (CMN 2289) in lateral (E, F), medial (G, H), and anterior (I, J) views.
Fig 14.
Left and right pterygoids of Edmontosaurus regalis (CMN 2289) in anterolateral (A, B) and posteromedial (C, D) views.
Fig 15.
Anterior region of the neurocranium of Edmontosaurus regalis (CMN 2289) in left anterolateral (A) and right anterolateral (B) views. Posterior region of the neurocranium of Edmontosaurus regalis (CMN 2289) in left lateral (C) and right lateral (D) views.
Fig 16.
Left and right dentaries of Edmontosaurus regalis (CMN 2289) in lateral (A, B), medial (C, D), dorsal (E, F), ventral (G, H), and posterior (I, J) views.
Fig 17.
Incomplete, articulated right dentary, surangular, angular, splenial and articular of Edmontosaurus regalis (CMN 2288) in lateroventral (A), dorsomedial (B), dorsal (C), and ventral (D) views.
Fig 18.
Incomplete, articulated right surangular and angular of Edmontosaurus regalis (CMN 2289) in lateroventral (A), dorsomedial (B), and dorsal (C) views. Incomplete left angular of Edmontosaurus regalis (CMN 2289) in laterodorsal (D) and ventromedial (E) views. Partial right splenial of Edmontosaurus regalis (CMN 2289) in lateral (F), medial (G), and dorsal (H) views. Nearly complete, articulated left splenial and articular of Edmontosaurus regalis (CMN 2289) in lateral (I), medial (J), and dorsal (K) views.
Fig 19.
Dentitions of Edmontosaurus regalis (CMN 2289).
Exposed teeth in the middle of the left maxilla in labial (A) and occlusal (B) views. Exposed teeth in the middle of the left dentary in lingual (C) and occlusal (D) views. Positions of active teeth on the occlusal surface are indicated by blue arrows.
Fig 20.
Strict consensus of 24 most parsimonious trees resulting from the maximum parsimony analysis of Hadrosauroidea, showing the sister-group relationship between Hadrosaurinae and Lambeosaurinae within Hadrosauridae.
Numbers above lines represent bootstrap proportions, whereas those below lines represent Bremer decay values. Bootstrap proportions lower than 20 and Bremer decay values less than 2 are not shown.
Fig 21.
Time-calibrated cladogram of Hadrosaurinae derived from the strict consensus tree shown in Fig 20, with probability estimation of ancestral continental regions for all nodes of the taxon.
Blue stars indicate hadrosaurine species recovered from Appalachia, eastern North America.