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Brachiosaurus brancai is not Brachiosaurus Michael P. Taylor Palaeobiology Research Group School of Earth and Environmental Sciences University of Portsmouth Burnaby Road, Portsmouth PO1 3QL ENGLAND dino@miketaylor.org.uk. Brachiosaurus altithorax skeletal reconstruction
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Brachiosaurus brancai is not Brachiosaurus Michael P. Taylor Palaeobiology Research Group School of Earth and Environmental Sciences University of Portsmouth Burnaby Road, Portsmouth PO1 3QL ENGLAND dino@miketaylor.org.uk Brachiosaurus altithorax skeletal reconstruction (Taylor in press)
Brachiosaurus at O'Hare Airport, Chicago Brachiosaurus at O'Hare Airport, Chicago
Brachiosaurus at O'Hare Airport, Chicago Brachiosaurus at O'Hare Airport, Chicago
Brachiosaurus at O'Hare Airport, Chicago Brachiosaurus at O'Hare Airport, Chicago
Brachiosaurus at O'Hare Airport, Chicago Brachiosaurus at O'Hare Airport, Chicago
Brachiosaurus at O'Hare Airport, Chicago Brachiosaurus at O'Hare Airport, Chicago
Brachiosaurus at O'Hare Airport, Chicago Brachiosaurus at O'Hare Airport, Chicago
Brachiosaurus at O'Hare Airport, Chicago Brachiosaurus at O'Hare Airport, Chicago But we don't have the head Or the neck Or the scapula and anterior dorsals Or most of the tail Or the lower forelimbs and forefeet Or the lower hindlimbs and hindfeet But we don't have the head Or the neck Or the scapula and anterior dorsals Or most of the tail Or the lower forelimbs and forefeet Or the lower hindlimbs and hindfeet
Brachiosaurus brancai at the Humboldt Museum Brachiosaurus brancai at the Humboldt Museum
Brachiosaurus brancai at the Humboldt Museum Brachiosaurus brancai at the Humboldt Museum Most of what we think we know about Brachiosaurus, we really know about Brachiosaurus brancai.
Brachiosaurus brancai at the Humboldt Museum Brachiosaurus brancai at the Humboldt Museum Most of what we think we know about Brachiosaurus, we really know about Brachiosaurus brancai. But is it Brachiosaurus?
Brachiosaurus altithorax Riggs 1903 Elements from Riggs (1904)
Brachiosaurus brancai Janensch 1914 Elements from Janensch (1922, 1929, 1935-1936, 1950, 1961)
Migeod's Tendaguru brachiosaur (at the BMNH) Migeod (1931: fig. 1)
The Potter Creek humerus (found 1943) Jensen (1987: fig 3E) Photographs by M. Brett-Surman
Subsequent Potter Creek material (1971-1975) Jensen (1987: fig 3E)
Dry Mesa (“Ultrasauros”) scapulocoracoid Curtice et al. (1996: fig. 1A) Referred to B. altithorax by Paul (1988)
Felch Quarry skull Modified from Carpenter and Tidwell (1998: fig. 2) Carpenter and Tidwell (1998: fig. 1)
Jensen/Jensen rib (Jensen 1987: fig. 6B) Other bits and pieces OMNH 01138 (Bonnan and Wedel 2004:fig. 1) BYU 12866 and 12867
NONE of the referred Brachiosaurus altithorax material is convincing. NONE of the referred Brachiosaurus altithorax material is convincing. All we really have to go on is the holotype FMNH P25107
B. brancai compared with Brachiosaurus holotype Janensch mostly noted general similarity: “[Brachiosaurus brancai] is so close to the genus Brachiosaurus, so far as a the present state of preparation allows a judgement, that there was no recognisable reason to hold [it] separate from Brachiosaurus.” – Janensch (1914:83) “The dorsal vertebrae of the African Brachiosaurus brancai correspond extensively to those of Brachiosaurus altithorax” – Janensch (1950:72) “The humerus of the type species of the genus Brachiosaurus altithorax Riggs (1904) from the Morrison Formation, is in broad terms so similar in outline to Br. brancai that a detailed comparison is unnecessary.” – Janensch (1961:187)
Janensch's 13 putative synapomorphies OK OK OK OK
Janensch's 13 putative synapomorphies OK OK Four synapomorphies Four synapomorphies OK OK
The subgenus Brachiosaurus (Giraffatitan) Erected by Paul (1988) for “Brachiosaurus” brancai Separation asserted but not demonstrated. “The caudals, scapula, coracoid, humerus, ilium and femur of B. altithorax and B. brancai are very similar ... it is in the dorsal column and trunk that the significant differences occur.” Comparisons based in part on the dorsal BYU 9044 And on the scapulocoracoid BYU 9462
The subgenus Brachiosaurus (Giraffatitan) Erected by Paul (1988) for “Brachiosaurus” brancai Separation asserted but not demonstrated. “The caudals, scapula, coracoid, humerus, ilium and femur of B. altithorax and B. brancai are very similar ... it is in the dorsal column and trunk that the significant differences occur.” Comparisons based in part on the dorsal BYU 9044 ... which belongs to the diplodocid Supersaurus. And on the scapulocoracoid BYU 9462
The subgenus Brachiosaurus (Giraffatitan) Erected by Paul (1988) for “Brachiosaurus” brancai Separation asserted but not demonstrated. “The caudals, scapula, coracoid, humerus, ilium and femur of B. altithorax and B. brancai are very similar ... it is in the dorsal column and trunk that the significant differences occur.” Comparisons based in part on the dorsal BYU 9044 ... which belongs to the diplodocid Supersaurus. And on the scapulocoracoid BYU 9462 ... which is (bad) circular reasoning
Element-by-element comparisons Mostly based on personal examination. But Riggs's and Janensch's images are better than my photographs.
Dorsal ribs Variation: serial and individual and asymmetrical
Sacrum ? ?