Brachiosaurus brancai

1
Brachiosaurus brancai is not Brachiosaurus Micha
el P. Taylor Palaeobiology Research Group School
of Earth and Environmental Sciences University of
Portsmouth Burnaby Road, Portsmouth PO1
3QL ENGLAND dino_at_miketaylor.org.uk
Brachiosaurus altithorax skeletal
reconstruction (Taylor in press)?
2
Brachiosaurus at O'Hare Airport, Chicago
Brachiosaurus at O'Hare Airport, Chicago
3
Brachiosaurus at O'Hare Airport, Chicago
Brachiosaurus at O'Hare Airport, Chicago
4
Brachiosaurus at O'Hare Airport, Chicago
Brachiosaurus at O'Hare Airport, Chicago
5
Brachiosaurus at O'Hare Airport, Chicago
Brachiosaurus at O'Hare Airport, Chicago
6
Brachiosaurus at O'Hare Airport, Chicago
Brachiosaurus at O'Hare Airport, Chicago
7
Brachiosaurus at O'Hare Airport, Chicago
Brachiosaurus at O'Hare Airport, Chicago
8
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
9
Brachiosaurus brancai at the Humboldt Museum
Brachiosaurus brancai at the Humboldt Museum
10
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.
11
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?
12
Brachiosaurus altithorax Riggs 1903
Elements from Riggs (1904)?
13
Brachiosaurus brancai Janensch 1914
Elements from Janensch (1922, 1929, 1935-1936,
1950, 1961)?
14
Migeod's Tendaguru brachiosaur (at the BMNH)?
Migeod (1931 fig. 1)?
15
The Potter Creek humerus (found 1943)?
Jensen (1987 fig 3E)? Photographs by M.
Brett-Surman
16
Subsequent Potter Creek material (1971-1975)?
Jensen (1987 fig 3E)?
17
Dry Mesa (Ultrasauros) scapulocoracoid
Curtice et al. (1996 fig. 1A)? Referred to B.
altithorax by Paul (1988)?
18
Felch Quarry skull
Modified from Carpenter and Tidwell (1998 fig.
2)? Carpenter and Tidwell (1998 fig.
1)?
19
Jensen/Jensen rib (Jensen 1987 fig. 6B)?
Other bits and pieces
OMNH 01138 (Bonnan and Wedel 2004fig. 1)?
BYU 12866 and 12867
20
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
21
B. brancai compared with Brachiosaurus holotype
Janensch mostly noted general similarity Brach
iosaurus 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 (191483)? The
dorsal vertebrae of the African Brachiosaurus
brancai correspond extensively to those of
Brachiosaurus altithorax Janensch
(195072)? 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
(1961187)?
22
Janensch's 13 putative synapomorphies
23
Janensch's 13 putative synapomorphies
24
Janensch's 13 putative synapomorphies
25
Janensch's 13 putative synapomorphies
OK
OK
OK
OK
26
Janensch's 13 putative synapomorphies
OK
OK
Four synapomorphies
Four synapomorphies
OK
OK
27
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
28
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
29
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
30
Element-by-element comparisons
Mostly based on personal examination. But
Riggs's and Janensch's images are better than my
photographs.
31
Anterior dorsal vertebrae
32
Anterior dorsal vertebrae
33
Anterior dorsal vertebrae
34
Anterior dorsal vertebrae
35
Anterior dorsal vertebrae
36
Anterior dorsal vertebrae
37
Anterior dorsal vertebrae
38
Anterior dorsal vertebrae
39
Anterior dorsal vertebrae
40
Posterior dorsal vertebrae
41
Posterior dorsal vertebrae
42
Posterior dorsal vertebrae
43
Dorsal ribs
44
Dorsal ribs
45
Dorsal ribs
46
Dorsal ribs
47
Dorsal ribs
Variation serial and individual and asymmetrical
48
Sacrum
49
Sacrum
?
?
50
2nd caudal vertebra
51
2nd caudal vertebra
52
2nd caudal vertebra
53
2nd caudal vertebra
54
2nd caudal vertebra
55
2nd caudal vertebra
56
2nd caudal vertebra
57
2nd caudal vertebra
58
(Aside does B. brancai have pneumatic caudals?)?
59
(Aside does B. brancai have pneumatic caudals?)?
60
(Aside does B. brancai have pneumatic caudals?)?
61
Coracoid
62
Coracoid
63
Coracoid
64
Coracoid
65
Coracoid
66
Humerus
67
Humerus
GI 7.53 (ratio of length to width)?
GI 8.69 (range 7.869.19)?
68
Humerus
GI 7.53 (ratio of length to width)?
GI 8.69 (range 7.869.19)?
69
Humerus
GI 7.53 (ratio of length to width)?
GI 8.69 (range 7.869.19)?
70
Humerus
Probably just damage
GI 7.53 (ratio of length to width)?
GI 8.69 (range 7.869.19)?
71
Ilium
72
Ilium
73
Ilium
74
Ilium
75
Ilium
76
Femur
77
Femur
78
Femur
79
Femur
80
Summary

• All informative elements differ between species
• Dorsal vertebrae 10 differences
• 2nd Caudal vertebra 7 differences
• Coracoid 4 differences
• Humerus 3 differences
• Ilium 4 differences
• Femur 3 differences
• Brachiosaurus altithorax and Brachiosaurus
  brancai
• differ more than Diplodocus and Barosaurus.

81
Systematic palaeontology
DINOSAURIA Owen, 1842 SAURISCHIA Seeley, 1888
SAUROPODA Marsh, 1878 NEOSAUROPODA
Bonaparte, 1986 MACRONARIA Wilson and
Sereno, 1998 TITANOSAURIFORMES Salgado,
Coria and Calvo, 1997 BRACHIOSAURIDAE
Riggs, 1904 BRACHIOSAURUS Riggs,
1903 BRACHIOSAURUS ALTITHORAX
Riggs, 1903 Holotype--FMNH P
25107 GIRAFFATITAN Paul, 1988
GIRAFFATITAN BRANCAI (Janensch, 1914)?
Lectotype--HMN SII
82
Systematic palaeontology
DINOSAURIA Owen, 1842 SAURISCHIA Seeley, 1888
SAUROPODA Marsh, 1878 NEOSAUROPODA
Bonaparte, 1986 MACRONARIA Wilson and
Sereno, 1998 TITANOSAURIFORMES Salgado,
Coria and Calvo, 1997 BRACHIOSAURIDAE
Riggs, 1904 BRACHIOSAURUS Riggs,
1903 BRACHIOSAURUS ALTITHORAX
Riggs, 1903 Holotype--FMNH P
25107 GIRAFFATITAN Paul, 1988
GIRAFFATITAN BRANCAI (Janensch, 1914)?
Lectotype--HMN SII Sorry!
83
Phylogenetic analysis
Are Brachiosaurus and Giraffatitan closely
related? I re-scored the matrix of Harris
(2006)? with separate Brachiosaurus and
Giraffatitan OTUs. (By the way, 13 of the
compound Brachiosaurus OTU's 331 characters were
mis-scored -- 4.)?
84
Phylogenetic analysis
Brachiosauridae remains monophyletic
85
Phylogenetic analysis

• Brachiosauridae remains monophyletic, but
• Only one more step needed to split them up

86
Phylogenetic analysis

• Brachiosauridae remains monophyletic, but
• Only one more step needed to split them up
• What would happen if we added other
  brachiosaurs?

87
Differences in body proportions
The trunk is about 23 longer in
Brachiosaurus Tail is deeper and probably
longer Humeri may have been laterally
deflected More robust humeri gt may have
carried a larger proportion of mass
88
Giraffatitan reconstruction (Paul 1988)?
89
Brachiosaurus reconstruction (Taylor in press)?
90
Acknowledgements

• I thank ...
• Bill Simpson, David Unwin, Wolf-Dieter Heinrich
• and Sandra Chapman for access to specimens.
• Phil Mannion for photographs
• Gerhard Maier for translations of Janensch.
• Jerry Harris and Matt Wedel for reviews
• And I really am sorry about the name
  Giraffatitan.