[D] Brachylophosaurus [Si] [Su] [sG]
Describer
Sternberg, 1953
Time
Cretaceous Late Campanian
Classification
Ornithischia Ornithopoda Hadrosauridae Hadrosaurinae Brachylophosaurini [Maiasaurini] [Brachylophosaurs]
Diet
Herbivore
Fossilsite
Canada, US
Fall Under
Brachylophosaurus canadensis
Length
7 meter
Info
Genus - Skull
Brachylophosaurus (Sternberg, 1953) > Brachylophosaurus canadensis (Sternberg, 1953) >> Brachylophosaurus goodwini (Horner, 1988)
Unnamed taxon = Brachylophosaurs.
The species Brachylophosaurus goodwini is named by Jack Horner after Mark Goodwin, a preparator of the University of California at Berkeley\\\\\\\\\\\\\\\'s Museum of Paleontology, who discovered the type specimen.
The genus Brachylophosaurus and its type species Brachylophosaurus canadensis were originally described by Charles M. Sternberg in 1953 -it was one of the few dinosaurs to be described during the 1950s - from the Judith River Formation (then called the Oldman Formation) of Alberta, which is famous fot its marvelously preserved Late Cretaceous dinosaurs.
Horner\\\\\\\\\\\\\\\'s new species, however, is from the Judith River Formation of Montana, which is notorious for its fragmentary and problematical dinosaur remains. The type specimen of Brachylophosaurus goodwini is a partial skull, and fortunately enough of it exists that it can be referred with some confidence to the genus Brachylophosaurus
Diagnosis of genus (as for the type species)
Skull subrectangular with relatively deep snout nasals geatly developed into paddle-like solid crest extending caudodorsally over dorsal region of skull; nasals heaving cranio-caudally oriented groove that terminates in elongated foramen, located medial to prefrontal; prefrontal projecting caudally, resting doromedially over rostral process of postorbital, more caudally extending ventromedially, underlying nasal; jugal having ventrally projected semocircular flange, depressed dorsal surface of frontal between nasal and postorbital joint; short exoccipital-supraoccipiotal roof caudal and dorsal to foramen magnum; forarm verry long and slender due to elongation of radius and ulna. (Prieto-Márquez 2001)
Marquez, A.P. (2005) New information on the cranium of Brachylophosaurus canadensis (Dinosauria, Hadrosauridae), with a revision of its phylogenetic position. Journal of Vertebrate Paleontology, 25(1):144-156
Abstract
The cranium of the hadrosaurid dinosaur Brachylophosaurus canadensis is redescribed on the basis of abundant and complete material from the Lower Campanian Judith River Formation of Malta, northeastern Montana. The diagnosis of this taxon is emended, and the species Brachylophosaurus goodwini is now considered to be a junior synonym of Brachylophosaurus canadensis.
Autapomorphies of Brachylophosaurus are: nasal greatly developed into paddle-like solid crest extending caudodorsally, overhanging dorsal region of skull; nasal possessing anteroposteriorly oriented groove terminating in elongated foramen located medial to prefrontal; prefrontal projecting posteriorly and resting dorsomedially over anterior process of postorbital and, more posteriorly, extending ventromedially under nasal; only anterior sharp tip of lacrimal contacting maxilla; jugal with ventrally projecting semicircular flange; extremely elongated, rod-like anterodorsal process of maxilla projecting medial to narial cavity along most of anteroposterior length of external naris; anteroposteriorly short exoccipital-supraoccipital roof posterior and dorsal to foramen magnum.
Most autapomorphies of the junior synonym species Brachylophosaurus goodwini originated from misplacement of a nasal fragment and individual variation of the jugal. The new osteological information supports Brachylophosaurus canadensis as the sister taxon to Maiasaura peeblesorum, and suggests that the two taxa form a robust and basal clade within the Hadrosaurinae. Two new characters are discussed as phylogenetically informative for hadrosaurids: the mediolateral and anteroposterior predentary proportions and the length of the prequadratic process of the squamosal.
Sternberg, 1953
Time
Cretaceous Late Campanian
Classification
Ornithischia Ornithopoda Hadrosauridae Hadrosaurinae Brachylophosaurini [Maiasaurini] [Brachylophosaurs]
Diet
Herbivore
Fossilsite
Canada, US
Fall Under
Brachylophosaurus canadensis
Length
7 meter
Info
Genus - Skull
Brachylophosaurus (Sternberg, 1953) > Brachylophosaurus canadensis (Sternberg, 1953) >> Brachylophosaurus goodwini (Horner, 1988)
Unnamed taxon = Brachylophosaurs.
The species Brachylophosaurus goodwini is named by Jack Horner after Mark Goodwin, a preparator of the University of California at Berkeley\\\\\\\\\\\\\\\'s Museum of Paleontology, who discovered the type specimen.
The genus Brachylophosaurus and its type species Brachylophosaurus canadensis were originally described by Charles M. Sternberg in 1953 -it was one of the few dinosaurs to be described during the 1950s - from the Judith River Formation (then called the Oldman Formation) of Alberta, which is famous fot its marvelously preserved Late Cretaceous dinosaurs.
Horner\\\\\\\\\\\\\\\'s new species, however, is from the Judith River Formation of Montana, which is notorious for its fragmentary and problematical dinosaur remains. The type specimen of Brachylophosaurus goodwini is a partial skull, and fortunately enough of it exists that it can be referred with some confidence to the genus Brachylophosaurus
Diagnosis of genus (as for the type species)
Skull subrectangular with relatively deep snout nasals geatly developed into paddle-like solid crest extending caudodorsally over dorsal region of skull; nasals heaving cranio-caudally oriented groove that terminates in elongated foramen, located medial to prefrontal; prefrontal projecting caudally, resting doromedially over rostral process of postorbital, more caudally extending ventromedially, underlying nasal; jugal having ventrally projected semocircular flange, depressed dorsal surface of frontal between nasal and postorbital joint; short exoccipital-supraoccipiotal roof caudal and dorsal to foramen magnum; forarm verry long and slender due to elongation of radius and ulna. (Prieto-Márquez 2001)
Marquez, A.P. (2005) New information on the cranium of Brachylophosaurus canadensis (Dinosauria, Hadrosauridae), with a revision of its phylogenetic position. Journal of Vertebrate Paleontology, 25(1):144-156
Abstract
The cranium of the hadrosaurid dinosaur Brachylophosaurus canadensis is redescribed on the basis of abundant and complete material from the Lower Campanian Judith River Formation of Malta, northeastern Montana. The diagnosis of this taxon is emended, and the species Brachylophosaurus goodwini is now considered to be a junior synonym of Brachylophosaurus canadensis.
Autapomorphies of Brachylophosaurus are: nasal greatly developed into paddle-like solid crest extending caudodorsally, overhanging dorsal region of skull; nasal possessing anteroposteriorly oriented groove terminating in elongated foramen located medial to prefrontal; prefrontal projecting posteriorly and resting dorsomedially over anterior process of postorbital and, more posteriorly, extending ventromedially under nasal; only anterior sharp tip of lacrimal contacting maxilla; jugal with ventrally projecting semicircular flange; extremely elongated, rod-like anterodorsal process of maxilla projecting medial to narial cavity along most of anteroposterior length of external naris; anteroposteriorly short exoccipital-supraoccipital roof posterior and dorsal to foramen magnum.
Most autapomorphies of the junior synonym species Brachylophosaurus goodwini originated from misplacement of a nasal fragment and individual variation of the jugal. The new osteological information supports Brachylophosaurus canadensis as the sister taxon to Maiasaura peeblesorum, and suggests that the two taxa form a robust and basal clade within the Hadrosaurinae. Two new characters are discussed as phylogenetically informative for hadrosaurids: the mediolateral and anteroposterior predentary proportions and the length of the prequadratic process of the squamosal.