And the Largest Theropod Is....

["Mickey Mortimer" <Mickey_Mortimer111@msn.com>]

It's often asked what the largest known theropod is. To "resolve" this
question, I've estimated the total length and mass of the largest known
specimens of a number of theropods thought at one time or another to be
particularly large. Here they are in order from smallest to largest. Note
the large amount of uncertainty present in each size estimate. Organisms
will often vary proportionally within the same species, not to mention
higher taxonomic divisions. Most of my estimates were done using only a few
elements, so proportional differences might not have been adequatly dealt
with. Then there's allometric scaling that's only been well studied in
tyrannosaurids (Currie, 2003), but undoubtedly affected other theropods. I
did not take this into account. And don't even get me started on mass
estimates. The technique used to estimate mass varied between specimens,
mass varies by the cube of distance so is much less accurate at large sizes,
mass probably varied within an individual depending on external variables,
etc.. But this is the best data I could compute, so enjoy!

undescribed Westfahlen tetanurine (anon. 1999)
(~7-8 m; 750 kg-1.2 tons) (skull ~1.0 m) premaxilla, maxilla (517 mm),
lacrimal?, postorbital?, anterior dentary, teeth, fused gastralium, two
caudal vertebrae, one complete dorsal rib, four rib fragments, ilium,
fibulae (750 mm), other elements, gastrolith
The infamous "Das Monster von Minden", this basal tetanurine really wasn't
that large. The maxillae suggest a cranial length of a meter, and this and
the fibular(?) length both indicate a total length of only 7-8 meters.

Ceratosaurus? ingens (Janensch 1920)
(HMN MB. R1050) (~7-8 m; ~1.1-1.7 tons) teeth (to 120 mm)
Thought to be quite large by Paul and others, it is... for Ceratosaurus.
Though one cannot be certain where in the tooth row the 120 mm long type
(excluding root) belongs, the animal would only be 7-8 meters long if it
happened to be one of the larger maxillary crowns. The holotype quadrate of
Ceratosaurus roechlingi is actually from a demonstrably larger individual,
about 9.3 meters long.

Megaraptor namunhuaiquii Novas 1998
(MCF-PVPH 79) (~9.5 m; ~1.4 tons) ulna (332 mm), phalanx I-1 (188 mm),
distal metatarsal III (~453 mm), pedal ungual II (310 mm)
The estimate is based on Deinonychus, extrapolating from metatarsal width.

Therizinosaurus cheloniformes Maleev 1954
(IGM 100/15) (~9.6 m; ~6.2 tons) tooth, scapula (670 mm), coracoid (360 mm),
humerus (760 mm), radius (550.4 mm), ulna (620.2 mm), semilunate carpal,
distal carpal, metacarpal I (145.5 mm), metacarpal II (286.8 mm), phalanx
II-1 (141.7 mm), phalanx II-2 (145.8 mm), manual ungual II (~585 mm),
metacarpal III (191.6 mm), dorsal ribs, gastralia
Heavier than all but a few of the largest taxa, but not as long as most.

"Allosaurus" tendagurensis Janensch 1925
(HM 67) (~10 m; ~2.5 tons) partial tibia (~910 mm)
Though huge, this tibia is virtually never mentioned as being from one of
the largest theropods known. The estimate is based on Allosaurus specimens,
but as "A." tendagurensis was a more basal tetanurine, one might expect the
actual length to be longer.

Yangchuanosaurus shangyouensis Dong, Li, Zhou and Chang 1978
(CV 00216; holotype of Yangchuanosaurus magnus) (10.5 m; 3.1 tons) skull
(1.11 m), lower jaw, three cervical vertebrae, two dorsal vertebrae, sacrum,
six caudal vertebrae, ilium, pubis, ischium, femur (1.2 m)

Saurophaganax maximus Chure 1995
(OMNH 1708) (10.9 m; 3.2 tons) femur (1135 mm)
?(NMMNH P-26083) (9.9 m; 2.6 tons) sacral vertebrae 4 and 5, caudal
vertebrae 1-4, chevrons 1-4, ilium, ischia, femur (1.04 m), tibia (910 mm),
fibula, pedal phalanges (Williamson and Chure 1996)
Whether this is Allosaurus or not is a subjective decision, though you might
as well equate "Allosaurus" with "Allosauridae" if you think so. The type
material includes at least two individuals of comparable (and huge) size,
along with one/some smaller specimens. The Epanterias specimen was seemingly
larger however. NMMNH P-26083 could be Allosaurus or Saurophaganax.

Chilantaisaurus tashuikensis Hu 1964
(IVPP V2884) (~10-11 m; ~2.6 tons) tooth, two proximal caudal vertebrae
(lost), humerus (595 mm), manual ungual I, fragmentary ilium (lost), femora
(1.19 m, lost), tibia (954 mm, lost), fibula (lost), metatarsal II (400 mm),
metatarsal III (450 mm), metatarsal IV (395 mm)
A very large theropod (much moreso than "C." maortuensis), its size is made
even more uncertain, as we do not know if its proportions resembled
megalosaurids or spinosaurids more.

Suchomimus tenerensis Sereno, Beck, Dutheil, Gado, Larsson, Lyon, Marcot,
Rauhut, Sadleir, Sidor, Varricchio, Wilson and Wilson 1998
(MNN GDF500) (11.0 m, 2.9-4.8 tons) third cervical rib, fifth cervical rib,
eighth cervical rib, first dorsal vertebra, second dorsal vertebra, third
dorsal vertebra, fifth dorsal vertebra, sixth dorsal vertebra, seventh
dorsal vertebra, eighth dorsal vertebra, ninth dorsal vertebra, tenth dorsal
neural spine, eleventh dorsal centrum, thirteenth dorsal vertebra,
fourteenth dorsal vertebra, fifteenth dorsal vertebra, sixteenth dorsal
vertebra, ten dorsal ribs, gastralia, sacral neural spines 3-5, caudal
transverse processes 2-5, caudal neural spines 1-5, six mid caudal centra,
distal caudal vertebra, three chevrons, scapula, coracoid, humerus (560 mm),
radius (255 mm), ulna, manual ungual I (264 mm), manual ungual II (165 perp.
to art.), metacarpal III (130 mm), manual ungual III (120 perp. to art.),
ilium, pubis, ischium, femur (1.075 m), tibia (945 mm), pedal phalanx
(Sereno et al. 1998)
Very large, and only subadult.

Tarbosaurus bataar (Maleev 1955) Rozhdestvensky 1965
(IGM 551-1) (11.0 m, ~6 tons) skull (~1.35 m), dentary (551 mm), posterior
cervical vertebrae, first four dorsal vertebrae
Several large specimens are known, but none comparable to known
Tyrannosaurus specimens. The largest described is the holotype.

Carcharodontosaurus saharicus (Daperet and Savornin 1925) Stromer 1931
(IPHG 1922 X46) (~11.0 m; ~2.8 tons) maxilla lacking nasal process, teeth,
nasal, parietal, cervical vertebrae, caudal vertebrae, manual ungual, ilium,
pubis (>800 mm), femur (1.26 m), fibula (880 mm) (Stromer 1931, Rauhut 1995)
(SGM-Din 1) (~11.1 m; ~2.9 tons) skull lacking premaxilla (~1.6 m) (Sereno,
Dutheil, Iarochene, Larsson, Lyon, Magwene, Sidor, Varricchio and Wilson
1996)
Even the holotype of Carcharodontosaurus is huge, about as large as the
referred skull.

Deinocheirus mirificus Osmolska and Roniewicz 1967
(ZPAL MgD-I/6) (10-13 m; 2.4-4.3 tons) two ceratobranchials, three vertebral
fragments, seven partial dorsal ribs, gastralia fragments, nearly complete
scapulacoracoids (1.53 m), humeri (938 mm), radii (630 mm), ulnae (688 mm),
metacarpal I (214, 220 mm), phalanx I-1 (320 mm), manual ungual I,
metacarpal II (230 mm), phalanx II-1 (140 mm), phalanx II-2 (226, 229 mm),
manual ungual II (196 mm), metacarpal III (246, 245 mm), phalanx III-1 (110,
105 mm), phalanx III-2 (104, 100 mm), phalanx III-3 (186, 182 mm), manual
ungual III (Osmolska and Roniewicz 1967)
The estimates are based on various ornithomimosaur species.

Acrocanthosaurus atokensis Stovall and Langston 1950
(MOU 8-0-S8 or OMNH 10147) (11.7 m; 2.5 tons) two dorsal centra, four dorsal
neural spines, eight posterior dorsal ribs, first caudal vertebra, second
caudal vertebra (128 mm), third caudal vertebra (138 mm), fourth caudal
vertebra (140 mm), ninth caudal vertebra (149 mm), tenth caudal vertebra
(146 mm), eleventh caudal vertebra (141 mm), twelfth caudal vertebra (140
mm), eighteenth caudal vertebra, nineteenth caudal vertebra (131 mm),
twentieth caudal vertebra (134 mm), twenty-first caudal vertebra (135 mm),
twenty-second caudal vertebra, twenty-third caudal vertebra (124 mm),
proximal chevron, pubes, proximal femur (~950 mm), fragmentary tibia (~958
mm), metatarsal II (416 mm), metatarsal III (445 mm), phalanx III-1 (145 mm)
(Stovall and Langston 1950)
(NCSM 14345) (11.5 m; 2.4 tons) skull (1.23 m), mandible (1.315 m), cervical
rib, several dorsal ribs, gastralia, fourteen caudal vertebrae, six
chevrons, about ten partial vertebrae, scapulocoracoid (1.18 m), humerus
(370 mm), radius (220 mm), ulna (255 mm), ulnare, radiale, distal carpal
1+2, metacarpal I (62 mm), phalanx I-1 (111 mm), metacarpal II (116 mm),
phalanx II-1 (101 mm), phalanx II-2 (103 mm), manual ungual II, metacarpal
III (89 mm), phalanx III-1 (50 mm), phalanx III-2 (42 mm), phalanx III-3 (60
mm), manual ungual III, partial femur (~1.28 m), incomplete tibia (960 mm),
partial astragalus, calcaneum, metatarsal I (111 mm), phalanx I-1 (70 mm),
pedal ungual I, metatarsal II (410 mm), phalanx II-1 (55 mm), phalanx II-2
(122 mm), proximal metatarsal III (~440 mm), phalanx III-1 (160 mm), phalanx
III-2 (115 mm), proximal metatarsal IV, phalanx IV-1 (85 mm), phalanx IV-2
(70 mm), phalanx IV-3 (58 mm), metatarsal V (200 mm)
(OMNH 10168) vertebral fragments, ischium, femur
Both the paratype and new incomplete skeleton are comparable in size.

undescribed carcharodontosaurid (Coria and Currie 1997)
(MUCPv coll.) (11.8 m; 3.5 tons) eight individuals including tibia (1.06 m)
Though famous for a being a new contender for "largest theropod", I have yet
to see any evidence it was even as large as Gigantotosaurus' holotype.
Currie has said it might have been as large or larger, the original specimen
was only 8 meters, and the largest of three tibiae on the RTMP website was
"only" 1.06 meters. The latter would equate to a length of 11.8 meters,
smaller than Giganotosaurus' type. Yet the press has stated it was 10%
larger than the latter. Assuming the latter were true, it would be 13.7
meters and 5.5 tons.

Bahariasaurus ingens Stromer 1934
(HM 1922 X47) (11.9 m; ~2.5 tons) dorsal vertebra (200 mm), dorsal vertebra
(~180 mm), neural arch, rib fragment, sacral vertebra (~135 mm), sacral
vertebra (~120 mm), sacral vertebra (~120 mm), pubes (1.03 m), proximal
ischium (Stromer 1934)

Edmarka rex Bakker, Kralis, Siegwarth and Filla 1992
(CPS 1002) (~12 m; ~4 tons) incomplete scapula (~870 mm), partial coracoid
(CPS 1005) jugal (skull ~1.5 m)
(CPS 1010) pubis (845 mm)
The three specimens probably belong to the same individual. It rivals the
holotype of Epanterias in size.

Utahraptor ostrommaysorum Kirkland, Gaston and Burge 1993
(~12 m; ~2.7 tons) caudal vertebrae (Britt et al., 2001)
Based on undescribed specimens, this estimate comes from caudals reportedly
twice as long as those associated with a 565 mm femur.

Allosaurus fragilis Marsh 1877
(AMNH 680) (9.7 m; 2.3 tons) dorsals 5-7, four proximal caudal vertebrae,
ilium, pubes, ischia, femur (1.008 m), tibiae, fibulae, astragali,
calcaneum, metatarsus, pedal phalanges (Chure, 2001)
(AMNH 5767; holotype of Epanterias amplexus) (12.1 m; 4.5 tons) axis, sixth
or seventh cervical centrum, first dorsal neural arch, coracoid (328 mm
long), distal metatarsal IV
The largest "traditional" Allosaurus specimen I know of is AMNH 680, while
the Epanterias holotype is even larger. The fact a 12.1 meter specimen of a
taxon normally 7-9 meters exists just shows us how much variation can uccur
within a single species, and how little to trust any of our specimens as
being representative of their species.

Tyrannosaurus rex Osborn 1905
(FMNH PR2081, =BHI 2033; Sue) (11.2 m; 6.7 tons) skull (1.53 m), cervical
vertebrae, dorsal vertebrae, sacrum, proximal caudal vertebrae, scapula,
coracoid, humerus (37.3 mm), radius (17.3 mm), ulna (21.9 mm), metacarpal I
(6.4 mm), manual ungual I, metacarpal II (10.9 mm), phalanx II-1 (5.5 mm),
phalanx II-2 (7.9 mm), manual ungual II, pelvis, femur (1.38 m), tibia (1.2
m), fibula, pes
(MOR 980; Rigby specimen; material of Tyrannosaurus "imperator") (~10.6 m;
~5.7 tons) braincase, caudal vertebrae, pubes (1.33 m), limb elements
(MOR 1126; Celeste or C-rex) (12.3 m?; ~8.9 tons?) surangular, tooth, few
cervical vertebrae, cervical ribs, dorsal vertebrae 1-13, twenty-six dorsal
ribs, gastralia, sacrum, scapula, pubes, ischia, pedal phalanx
(UCMP 118742) (~13.6 m?, ~12 tons?) maxilla (skull ~1.75 m) (Carr 1999)
Sue is the largest relatively complete described specimen. Horner says
Celeste is 10% larger, but no measurements have been presented. Though
Paul's original estimate for the UCMP maxilla gave an estimate of 13.6
meters, but more recently he's said that it's about the length of Sue's.
Rigby's largest specimen on the other hand, has a pubis not much different
in size than the holotype.

Deltadromeus agilis Sereno, Dutheil, Iarochene, Larsson, Lyon, Magwene,
Sidor, Varricchio and Wilson 1996
(IPHG 1912 VIII) (13.3 m; ~3.5 tons) dorsal vertebra (220 mm), dorsal
vertebra (225 mm), dorsal vertebra (225 mm), caudal vertebra (155 mm),
caudal vertebra, caudal vertebra (170 mm), coracoid, pubes, femur (1.22 m),
proximal tibia, fibula
Ironically, this referred specimen seems to be longer than the
Carcharodontosaurus described alongside it by Sereno et al.. There is a
strong possibility Deltadromeus is a junior synonym of Bahariasaurus.

Giganotosaurus carolinii Coria and Salgado 1995
(MUCPv-Ch1) (12.5 m, 4.16 tons) (skull- ~1.8 m) premaxilla, maxilla, nasal,
lacrimal, postorbital, quadrate, braincase, anterior dentary, teeth, most
cervical vertebrae (including axis and eighth cervical), most dorsal
vertebrae, dorsal ribs, first caudal vertebra, caudal vertebrae 7-21, two
distal caudal vertebrae, eight chevrons, scapula (727 mm), coracoid, ilium
(1.54 m), pubes (1.11 m), ischia (1.2 m), femora (1.43 m), tibia (1.12 m),
fibula, metatarsi, pedal elements (Calvo and Salgado 1996)
(MUCPv-95) (13.5 m, 5.2 tons) (skull ~1.95 m) incomplete dentary, teeth
(Calvo and Coria, 2000)
The dentary is from a larger individual than the already huge type, often
said to be the largest theropod.

Spinosaurus aegyptiacus Stromer 1915
(IPHG 1912 VIII 19, destroyed) (~17.4 m, 12-19 tons) maxillary fragment,
incomplete dentary, nineteen teeth, two incomplete cervical vertebrae, seven
dorsal vertebrae (190-210 mm), dorsal ribs, gastralia, eight caudal centra
(MNHN SAM 124) (~15.9 m, 9-15 tons) (skull ~2 m) partial premaxillae,
partial maxillae, vomers, dentary fragment (Taquet and Russell 1998)
The largest named theropod, and probably the largest known. It beats the
nearest competitors by several meters, so I really don't see why it's not
more universally thought of as the largest. Even the rumored largest
carcharodontosaurs and tyrannosaurs are smaller. And like Suchomimus, the
holotype is a subadult.

Kelmayisaurus "gigantus" Grady 1993
This nomen nudum was listed in Grady's book as having an axial column 22
meters long. Though Grady said he got the name from Russell's notebook,
Russell hadn't heard of it. Dong's supposedly working on it, but everyone's
natural suspicion is that it's a sauropod. We'll have to see what happens if
it ever gets published, but I doubt the 22+ meter long theropod explanation
will hold.

Mickey Mortimer