Theropoda Marsh, 1881
Official Definition-
(Allosaurus fragilis <- Plateosaurus engelhardti, Heterodontosaurus tucki)
(Naish, Cau, Holtz, Fabbri and Gauthier, 2020; originally from Naish,
Cau, Holtz, Fabbri and Gauthier, in press vide Dal Sasso, Maganuco and
Cau, 2018; Registration Number 216)
Other definitions- (Passer domesticus <- Saltasaurus loricatus)
(Sereno, 2004; modified from Sereno, 1998; modified from Gauthier, 1986)
(Passer domesticus <- Cetiosaurus oxoniensis) (Holtz and Osmolska,
2004; modified from Gauthier, 1986)
(Allosaurus fragilis <- Morosaurus impar)
(modified from Kischlat, 2000)
(Allosaurus fragilis <- Plateosaurus engelhardti) (modified
from Clarke et al., 2004)
(Passer domesticus <- Diplodocus carnegii, Triceratops horridus) (Baron, Norman and Barrett, 2017)
= Goniopoda Cope, 1866
= Therophagi Jaekel, 1914
= Carnosauriformes Cooper, 1985
= Theropoda sensu Sereno, 1998
Definition- (Passer domesticus <- Saltasaurus loricatus) (modified)
= Theropoda sensu Kischlat, 2000
Definition- (Allosaurus fragilis <- Morosaurus impar) (modified)
= Theropoda sensu Clarke, Gauthier, de Queiroz, Joyce, Parham and Rowe, 2004
Definition- (Allosaurus fragilis <- Plateosaurus engelhardti)
= Theropoda sensu Holtz and Osmolska, 2004
Definition- (Passer domesticus <- Cetiosaurus oxoniensis) (modified)
= Theropoda sensu Baron, Norman and Barrett, 2017
Definition- (Passer domesticus <- Diplodocus carnegii, Triceratops horridus)
Other diagnoses- Marsh's (1881) original diagnosis consisted largely
of plesiomorphies- carnivorous; limb bones hollow; digits with prehensile claws;
digitigrade pes. The distal pubes are only fused in adult neotheropods. "Vertebrae
more or less cavernous" refers to the extremely constricted dorsal centra
of Allosaurus, which aren't present in most theropods. "Post-pubis
present" probably refers to Allosaurus' elongate pubic boot, which
is only present in some avetheropods.
Marsh (1884) added more plesiomorphies- premaxilla toothed; external nares placed
anteriorly; large antorbital fossa; forelimbs short; propubic pelvis.
Comments- Marsh (1881) named Theropoda as a dinosaur suborder containing
only the Allosauridae, in which he placed Allosaurus, Creosaurus
and Labrosaurus (both of the latter now recognized as synonyms of Allosaurus).
By 1884, Marsh had raised Theropoda to an order and expanded it to include all
carnivorous dinosaurs, as well as what are today recognized as basal sauropodomorphs
(often mixed with cranial elements of canivorous crurotarsans). This was the
standard for many decades, as seen in Romer's (1956) classic work, in which
theropods consist of coelurosaurs, carnosaurs and prosauropods. The monophyly
of theropods was questioned by Huene (1914), who placed most of the larger taxa
such as Allosaurus and Megalosaurus in Sauropodomorpha (his Pachypodosauria)
while the smaller taxa (which he named Coelurosauria) had branched off earlier.
In the 1960's, workers began to recognize the monophyly of coelurosaurs and
carnosaurs to the exclusion of basal sauropodomorphs (e.g. Colbert, 1964). Paul
(1984) was the first author to use a theropod phylogeny similar to todays, with
deinonychosaurs (albeit paraphyletic), tyrannosaurids, allosaurids, Eustreptospondylus,
Ceratosaurus and coelophysoids forming successively more distant sister
taxa to birds. Gauthier's (1984) thesis also had a modern topology, with deinonychosaurs,
ornithomimids, carnosaurs and ceratosaurs (the latter two improbably inclusive,
containing tyrannosaurids and coelophysoids respectively) successively further
from birds, and is the basis of our current nomenclature for major clades.
Goniopoda, Harpagosauria, Therophagi and Carnosauriformes- Cope (1866)
named Goniopoda for Dryptosaurus (his Laelaps) and Streptospondylus
(his Megalosaurus) based on his misinterpretation of their astragalus
as a fibula, as a fibula which wraps distally around the tibia would be unique.
The taxon was almost exclusively used by Cope through the 1880's for carnivorous
dinosaurs even after the astragalus was correctly identified. He eventually
gave it a scope and diagnosis similar to Marsh's Theropoda (e.g. Cope, 1883).
After Cope's death, Theropoda became the term almost exclusively used for carnivorous
dinosaurs.
Harpagosauria was seen as a paraphyletic order of dinosaurs by Haeckel (1866),
containing Megalosaurus, Plateosaurus and Pelorosaurus
(but not Iguanodon). Haeckel refers to these as the carnivorous dinosaurs,
which led Cope to synonymize the taxon with his Goniopoda (starting in 1870,
and consistantly misspelled Harpagmosauria). However, Haeckel's original usage
suggests it is instead the equivalent to Saurischia. Baur (1887) uses Harpagosauria
as a dinosaurian group containing only Goniopoda, with Sauropoda separate. Haeckel
(1895) later used Harpagosauria as a junior synonym for his new dinosaurian
taxon Dysdracones including both Arctopoda (containing basal sauropodomorphs)
and Theropoda, with sauropods now placed in his Eudracones that contained all
herbivorous dinosaurs. Harpagosauria was said to contain the carnivorous dinosaurs
with sharp teeth and claws. It has not been used since.
Therophagi was named by Jaekel (1914) for a saurischian group containing the
taxa then usually referred to Theropoda- anchisaurids, zanclodontids (mixing
sauropodomorph postcrania with crurotarsan crania), ceratosaurids, megalosaurids
and tyrannosaurids. Plateosauridae and Sauropoda were placed in the Allophagi
however. The names have not been used since.
Proposed as part of a cladistic reclassification of ornithischians, Carnosauriformes
was named by Cooper (1985) as a cohort of dinosaurs "retaining the primitive
condition of recurved thecodontian dentition with finely serrated cutting edges."
No justification for using this name over Theropoda was given, and it is today
rightfully considered a junior synonym.
Theropoda defined- Gauthier (1986) was the first to phylogenetically
define Theropoda, as "birds and all saurischians that are closer to birds
than they are to sauropodomorphs." Variations on this definition have been
most common, with Sereno (1998) using Neornithes and Saltasaurus, specified
by Sereno (2004) as Passer domesticus and Saltasaurus loricatus.
Holtz and Osmolska (2004) chose Cetiosaurus oxoniensis as the sauropodomorph
specifier instead. However, this class of definition violates Phylocode Recommendation
11A- "Definitions of converted clade names should be stated in a way that
attempts to capture the spirit of traditional use to the degree that it is consistent
with the contemporary concept of monophyly." While birds are currently
thought to be theropods, this was not the consensus until over a century after
Theropoda was named. Similarly, Clarke et al.'s (2004) definition using Plateosaurus
engelhardti as an external specifier is problematic since basal sauropodomorphs
were often included in Theropoda until the 1960s. Kischlat (2000) suggested
all taxa closer to Allosaurus than to Morosaurus, which is valid
in using taxa Marsh (1881) and everyone since have recognized as being theropod
and non-theropod. The official definition by Naish et al. (2020) retained Allosaurus but also used Plateosaurus and the basal ornithischian Heterodontosaurus.
Ex-theropods- Numerous taxa (at least 130) have been incorrectly placed
in Theropoda in the past, including ornithosuchids, poposaurids, most basal
avemetatarsalians and basal sauropodomorphs, and many Triassic archosauriforms
known only from teeth. This site has an
entire section devoted to ex-theropods, so they are not discussed further
here.
References- Cope, 1866. [On the anomalous relations existing between
the tibia and fibula in certain of the Dinosauria]. Proceedings of the Academy
of Natural Sciences of Philadelphia. 18, 316-317.
Haeckel, 1866. Generelle Morphologie der Organismen. Allgemeine Grundzuge der
organischen Formen Wissenschaft, mechanisch begrundet durch die von Charles
Darwin reformiete Deszendenz-Theorie. II. Allgemeine Entwicklungsgeschichte
der Organismen. Kritische Grundzuge der mechanischen Wissenschaft von dan entstehenden
Formen der Organismen, begrundet durch die Deszendenz-Theorie. Georg Reimer. 462 pp.
Cope, 1870. Synopsis of the extinct Batrachia and Reptilia of North America.
Transactions of the American Philosophical Society. 14, 1-252.
Marsh, 1881. Principal characters of American Jurassic dinosaurs. Part V. American
Journal of Science. 21, 417-423.
Cope, 1883. On the characters of the skull in the Hadrosauridae. Proceedings
of the Philadelphia Academy of Natural Sciences. 35, 97-107.
Marsh, 1884. Principal characters of American Jurassic dinosaurs. Part VIII.
The order Theropoda. American Journal of Science. 27, 329-340.
Baur, 1887. On the phylogenetic arrangement of the Sauropsida. Journal of Morphology.
1, 93-104.
Haeckel, 1895. Systematische Phylogenie: Entwurf eines Nat�rlichen Systems
der Organismen auf Grund ihrer Stammesgeschichte. Dritter Theil: Systematische
Phylogenie der Wirbelthiere (Vertebrata). Georg Reimer, Berlin. 660 pp.
Huene, 1914. Das nat�rliche System der Saurischia [The systematics of the
Saurischia]. Centralblatt f�r Mineralogie, Geologie und Pal�ontologie.
1914, 154-158.
Jaekel, 1914. �ber die Wirbeltierfunde in der oberen Trias von Halberstadt.
Palaontologische Zeitschrift. 1(1), 155-215.
Romer, 1956. Osteology of the Reptiles. University of Chicago Press. 772 pp.
Colbert, 1964. Relationships of the saurischian dinosaurs. American Museum Novitates.
2181, 1-24.
Gauthier, 1984. A cladistic analysis of the higher systematic categories of
the Diapsida. PhD thesis. University of California. 564 pp.
Paul, 1984. The archosaurs: A phylogenetic study. Third Symposium on Mesozoic
Terrestrial Ecosystems, Short Papers. 175-180.
Cooper, 1985. A revision of the ornithischian dinosaur Kangnasaurus coetzeei
Haughton, with a classification of the Ornithischia. Annals of the South African
Museum. 95(8), 281-317.
Gauthier, 1986. Saurischian monophyly and the origin of birds. Memoirs of the
Californian Academy of Sciences. 8, 1-55.
Sereno, 1998. A rationale for phylogenetic definitions, with application to
the higher-level taxonomy of Dinosauria. Neues Jahrbuch f�r Geologie und
Pal�ontologie Abhandlungen. 210, 41-83.
Kischlat, 2000. Tecodoncios: A aurora dos Arcosaurios no Triassico. in Holz
and De Rose (eds.). Paleontologia do Rio Grande do Sul. 273-316.
Clarke, Gauthier, de Queiroz, Joyce, Parham and Rowe, 2004. A phylogenetic nomenclature
for the major clades of Amniota Haeckel 1866, with emphasis on Aves Linnaeus
1758. First International Phylogenetic Nomenclature Meeting, Abstracts. 30.
Holtz and Osm�lska, 2004. Saurischia. In Weishampel, Dodson and Osm�lska
(eds.). The Dinosauria. 2nd ed. University of California Press. 21-24.
Sereno, 2004. Phylogenetic nomenclature for stem crocodilians and birds, exclusive
of Pterosauria. First International Phylogenetic Nomenclature Meeting, Abstracts.
26.
Baron, Norman and Barrett, 2017. A new hypothesis of dinosaur
relationships and early dinosaur evolution. Nature. 543(7646), 501-506.
Dal Sasso, Maganuco and Cau, 2018. The oldest ceratosaurian
(Dinosauria: Theropoda), from the Lower Jurassic of Italy, sheds light
on the evolution of the three-fingered hand of birds. PeerJ. 6:e5976.
Naish,
Cau, Holtz, Fabbri and Gauthier, 2020. Theropoda O. C. Marsh 1881 [D.
Naish, A. Cau, T. R. Holtz, Jr., M. Fabbri, and J. A. Gauthier],
converted clade name. In de
Queiroz, Cantiono and Gauthier (eds.). Phylonyms: A Companion to the PhyloCode. Taylor & Francis Group. 1234-1245.
undescribed theropod (Fitch, Lovelace and Stocker, 2020)
Early-Mid Carnian, Late Triassic
Popo Agie Formation, Chugwater Group, Wyoming, US
Material- (UWGM 1975) anterior
dorsal vertebra, incomplete posterior dorsal vertebra (~21 mm), two incomplete
sacral vertebrae, metacarpal I (~9 mm), two partial manual unguals, proximal
ischium, proximal femur, tibial fragment, proximal fibula, astragalus (~21 mm trans),
distal metatarsal I, proximal metatarsal III
Comments- Discovered in 2013. Adding this to Nesbitt's Tawa matrix resulted Fitch et al. recovering the taxon as the sister taxon of Neotheropoda, more derived than Eodromaeus, Chindesaurus or Tawa. This relationship was based on elongated posterior dorsal centra shared with Eodromaeus
and neotheropods, and an astragalus much wider than anteroposteriorly deep,
very reduced surface for the ventromedial calcanear process on the
astragalus (absent in neotheropods), and a transversely expanded posterior
metatarsal III in proximal view shared with neotheropods. It was excluded
from Neotheropoda based on the lack of astragalocalcanear fusion (contra the
abstract), an anterolateral astragalar process and the proximal
elliptical astragalar fossa..
Reference- Fitch, Lovelace and
Stocker, 2020. The oldest dinosaur from the northern hemisphere and the
origins of Theropoda. The Society of Vertebrate Paleontology 80th
Annual Meeting, Conference Program. 140-141.
unnamed theropod (Pinheiro, 2016)
Early Norian, Late Triassic
Botucarai Hill, Caturrita Formation, Brazil
Material- (MMACR 039 T) distal femur (21 mm wide)
Comments- Discovered in 2015,
Pinheiro (2016) described this and referred it to
Neotheropoda. However, Ezcurra (2017) noted it lacks a
mediodistal crest unlike neotheropods, so may belong to a more basal
theropod.
Reference- Pinheiro, 2016. A
fragmentary dinosaur femur and the presence of Neotheropoda in the
Upper Triassic of Brazil. Revista Brasileira de Paleontologia. 19,
211-216.
Ezcurra, 2017. A new early coelophysoid neotheropod from the Late Triassic of northwestern Argentina. Ameghiniana. 54, 506-538.
Chilesaurus Novas, Salgado,
Suarez, Agnolin, Ezcurra, Chimento, Cruz, Isasi, Vargas and Rubilar-Rogers,
2015
C. diegosuarezi Novas, Salgado, Suarez, Agnolin, Ezcurra, Chimento,
Cruz, Isasi, Vargas and Rubilar-Rogers, 2015
Tithonian, Late Jurassic
Toqui Formation, Chile
Holotype-
(SNGM-1935) (~1.6 m; juvenile) partial skull, incomplete dentary, most
cervical vertebrae including fourth, over eleven incomplete to complete
dorsal vertebrae, dorsal rib fragments, second sacral vertebra (24.77
mm), third sacral vertebra (26.15 mm), fourth sacral vertebra (23.04
mm), fifth sacral vertebra (21.60 mm), sixth sacral vertebra (19.88
mm), first caudal vertebra (18.78 mm), second caudal vertebra (18.25
mm), third caudal vertebra (20.40 mm), fourth caudal vertebra, fifth
caudal vertebra (21.97 mm), sixth caudal vertebra (19.62 mm), seventh
caudal vertebra (20.11 mm), eighth caudal vertebra (21.30 mm), ninth
caudal vertebra (19.72 mm), tenth caudal vertebra (19.88 mm), eleventh
caudal vertebra, at least two proximal chevrons, scapulae (114.87,
116.33 mm), coracoids, humeri (97.84, 94.05 mm), radii (69.82, 68.29
mm), ulnae (~75.93 mm), distal carpal I, metacarpals I (27.15, 26.68
mm), phalanx I-1 (28.59 mm), metacarpals II (39.77, 39.23 mm),
phalanges II-1 (16.48, 15.97 mm), phalanx II-2 (13.61 mm), metacarpals
III, partial ilia, pubis (95.67 mm), ischium (101.17 mm), femora
(142.45, 140.75 mm), incomplete tibiae, fibula
Paratypes- (SNGM-1936) (~1.3 m;
juvenile) three incomplete anterior dorsal vertebrae, partial dorsal
rib, distal humerus, distal radius, incomplete ulna, metacarpals I
(24.81, 24.08 mm), phalanges I-1 (25.77 mm), metacarpal II (36.14 mm),
phalanx II-1, phalanx II-2 (14.67 mm), partial metacarpal III,
incomplete ilia (100.62 mm), pubes (97.73 mm), ischia (101.62 mm),
femur (114.59 mm), tibiae (128.22 mm), astragalus (27.36 mm trans),
metatarsal II (61.96 mm), phalanx II-1 (23.40 mm), phalanx II-2 (20.92
mm), metatarsal III (64.82 mm), metatarsal IV (55.49 mm)
(SNGM-1937) (~1.3 m; juvenile) forelimbs including coracoids, humeri (one partial; 87 mm),
radius (64 mm), ulna, metacarpal I (21.66 mm), phalanx I-1 (22.92 mm), manual ungual I (27.83 mm), metacarpal
II (31.52 mm), phalanx II-1 (18 mm), proximal phalanx II-2, manual ungual II (29 mm), metacarpal III (21.7
mm), tibiae (one partial; 114.61 mm), fibulae (one partial; ~144 mm), incomplete metatarsal
I, phalanx I-1 (33.60 mm), pedal ungual I (24.93 mm), incomplete metatarsal II,
phalanx II-1 (25.11 mm), phalanx II-2 (21.71 mm), pedal ungual II (31.81 mm), metatarsal III (71.15 mm), phalanx
III-1 (25.92 mm), phalanx III-2 (19.00 mm), phalanx III-3 (19.10 mm), pedal ungual III (~24.73 mm), metatarsal IV, phalanx
IV-1 (19.37 mm), phalanx IV-2 (17.47 mm), phalanx IV-3 (16.89 mm), phalanx IV-4 (15.52 mm)
(SNGM-1938) seven incomplete to fragmentary dorsal vertebrae, several
dorsal ribs, scapulae (160.05 mm), coracoids, humeri (130.86 mm),
radii, ulnae, both incomplete manus including manual ungual I (35.69
mm), metacarpals III (42.95, 40.11 mm)
Referred- (SNGM-307) pelvis (Chimento, 2015)
(SNGM-1887) distal carpal I, metacarpal I (49.95 mm), proximal phalanx I-1, incomplete
metacarpal II (75.65 mm), phalanx II-2, metacarpal III (62.71 mm), phalanx III-2?, phalanx
III-3? (Salgado et al., 2008)
(SNGM-1888) distal tibia, distal fibula, astragalus (61.50 mm trans), calcaneum, distal tarsal
IV, metatarsal II (121.95 mm), phalanx II-1 (45.77 mm), phalanx II-2 (41.93 mm), metatarsal III (133.35 mm), proximal phalanx
III-1, metatarsal IV (118.19 mm), proximal phalanx IV-1, incomplete pedal ungual (Salgado
et al., 2008)
(SNGM-1889) incomplete ilium (Salgado et al., 2008)
(SNGM-1890) metatarsal II (82.75 mm), metatarsal III (89.66 mm), partial metatarsal IV (Chimento, 2020)
(SNGM-1894) anterior dorsal centrum (Salgado et al., 2008)
(SNGM-1895) proximal tibia (Salgado et al., 2008)
(SNGM-1898) anterior dorsal centrum (Salgado et al., 2008)
(SNGM-1900) posterior dorsal centrum (Salgado et al., 2008)
(SNGM-1901) distal tibia (Salgado et al., 2008)
(SNGM-1903) anterior dorsal centrum (Salgado et al., 2008)
(SNGM-8193) pelvis (Chimento, 2015)
Diagnosis- (after Novas et al., 2015; note only convergences with closely
related taxa or alvarezsaurids are mentioned here) dentary deeper anteriorly
than posteriorly; teeth basally constricted (also in maniraptoriforms); teeth
serrated only apically; tooth crowns with large apical wear facets; posterior
cervical pleurocoels (also in basal neotheropods); cervicals with septate pleurocoels;
coracoid with transversely thick margins; manual phalanx II-2 shorter than II-1
(also in coelophysoids and some alvarezsaurids); manual digit III atrophied
(also in some alvarezsaurids); supratrochanteric process; ischiadic peduncle
of ilium robust (also in some alvarezsaurids); supracetabular crest absent;
pubis fully retroverted (also in derived alvarezsaurids); small pubic boot (also
in coelophysoids and derived alvarezsaurids); ischia connected through extended
medial lamina; femoral greater trochanter anteroposteriorly expanded (also in
alvarezsaurids); pedal digit I robust; metatarsal II transversely wider than
the other metatarsals (also in Tawa).
Other diagnoses- Contra Novas et al. (2015), the premaxilla is not particularly
short or deep. Fine serrations are plesiomorphic for archosaurs. The coracoid
is subquadrangular in megalosaurids, Ceratosaurus, coelophysoids and
many basal taxa. The pubis is not more rod-like than most neotheropods, nor is the
pubic apron narrower. Metatarsal I is proximally compressed transversely in
all theropods.
If I'm correct that Chilesaurus is a non-neotheropod sister to Daemonosaurus,
the following suggested characters by Novas et al. also don't apply- the plate-like
subnarial premaxillary process is shared with Daemonosaurus. The absent
mediodistal femoral crest is true in non-averostrans (and most alvarezsaurids).
The distally 'triangular' calcaneum is also primitive, being seen in e.g. Eoraptor
and Guaibasaurus. The lack of a fibular crest, astragalar ascending process
lower than its body, and robust and elongate metatarsal I are also true of most
non-neotheropods.
Comments- Novas et al. (2015) state there are four paratypes, but while
the other SNGM-193x series are obvious possibilities, it's unknown if this assumption
is correct and if so, what the other paratype is (SNGM-1887 and 1888 are most
complete, so most likely). A manual phalanx III-1 is also reported, but which
specimen preserves it is unknown. Salgado et al. (2008) report "articulated
phalanges ... III-2, and III-3 are preserved" in SNGM-1887, but Novas et
al. say metacarpal III's "digit comprises a single minute phalanx."
There are several elements illustrated in the skeletal or coded for (e.g. cervical
ribs, metatarsal V), whose existence must be confirmed by future publications.
Salgado et al. (2008) first reported Chilesaurus elements as non-tetanurine
Theropoda indet. (SNGM-1888, 1889, 1895, 1901) and Tetanurae indet. (SNGM-1887,
1894, 1898, 1900, 1903), due to the plesiomorphic tarsus and metatarsus yet
more derived-looking manus and keeled anterior dorsals. Once more complete specimens
were found, Novas et al. (2015) described them as a new taxon of non-orionidan
tetanurine. This was based on four datasets, but Chilesaurus is mis-
or uncoded for 12-14% of characters in at least three of them (Mortimer, online
2015). Once the datasets were corrected and improved, and Chilesaurus
was also analyzed in an unpublished coelurosaur matrix and Butler's ornithischian
matrix, the genus most parsimoniously groups with maniraptoriforms and more
precisely alvarezsaurids. It emerged strongly supported in that position in
my unpublished matrix and Nesbitt et al.'s dinosauromorph matrix once only verified
codings of Chilesaurus were used, took only 4 steps to move there without
any theropod characters in Butler's matrix, and is one of the most parsimonious
possibilities in Carrano et al.'s basal tetanurine matrix if only its verifiable
codings are used. A basal tetanurine position is strongly rejected if alvarezsaurids
are included (13 more steps in my matrix; 10 more in Butler's matrix). Yet both
of these placements seem unlikely due to the incongruities caused by inserting
Chilesaurus there, so that even though it's not most parsimonious, convergence
between Chilesaurus and tetanurines seems more likely than reversals
in Chilesaurus. The fact verifiable Chilesaurus emerges outside Neotheropoda in one of the most parsimonious trees when Velociraptor is excluded
from Nesbitt et al.'s matrix and only takes 1 more step to place there in Carrano
et al.'s matrix would then make sense. This would allow many characters to be
plesiomorphic (e.g. no fibular crest, short astragalar ascending process, large
pedal digit I), and also agrees with its placement close to Neotheropoda in Otero
and Pol's sauropodomorph-focused trees. In Nesbitt-based trees, when outside Neotheropoda, Chilesaurus emerged sister to Daemonosaurus with which
it shares- short snout; broad subnarial premaxillary process; three premaxillary
teeth (also in Tawa); decurved dentary; procumbant anterior teeth. However,
verifiable Chilesaurus falls out in Sauropodomorpha with 2-7 more steps,
and in Ornithischia with 4-8 more. So it could belong to those clades instead,
but more definite statements will require an osteology of the taxon to clear
up the coding incongruities and briefness of its original description.
References- Salgado, Cruz, Suarez, Fernandez, Gasparini, Palma-Heldt
and Fanning, 2008. First Late Jurassic dinosaur bones from Chile. Journal of
Vertebrate Paleontology. 28(2), 529-534.
Mortimer, online 2015. http://theropoddatabase.blogspot.com/2015/06/chilesaurus-brings-out-bandit-in-me.html
Chimento, 2015. Anatomia pelvica de un nuevo dinosaurio tetanuro (Dinosauria,
Theropoda) del Jurasico tardio de Chile. XXIX Jornadas Argentinas de Paleontolog�a
de Vertebrados, resumenes. Ameghiniana. 52(4) suplemento, 12.
Novas, Salgado, Suarez, Agnolin, Ezcurra, Chimento, Cruz, Isasi, Vargas and
Rubilar-Rogers, 2015. An enigmatic plant-eating theropod from the Late Jurassic
period of Chile. Nature. 522, 331-334.
Soto-Acuna, Otero, Rubilar-Rogers and Vargas, 2015. Arcosaurios no avianos de
Chile. Publicacion Ocasional del Museo Nacional de Historia Natural, Chile.
63, 209-263.
Chimento, Agnolin, Novas, Ezcurra, Salgado, Isasi, Suarez, de la Cruz, Rubilar-Rogers
and Vargas, 2017. Forelimb posture in Chilesaurus diegosuarezi (Dinosauria,
Theropoda) and its behavioral and phylogenetic implications. Ameghiniana. 54(5), 567-575.
Erythrovenator M�ller, 2021
= "Erythrovenator" M�ller, 2020 online
E. jacuiensis M�ller, 2021
= "Erythrovenator jacuiensis" M�ller, 2020 online
Middle Carnian-Early Norian, Late Triassic
Niemeyer Site, Santa Maria or Caturrita Formation, Candelaria Sequence, Brazil
Material- (CAPPA/UFSM 0157) proximal femur (~190 mm)
Diagnosis- (after M�ller, 2021) absence of a raised dorsolateral trochanter of the femur; absence of a folded anteromedial tuber.
Comments- This was discovered
between 2014 and 2016 and initially described as cf. Dinosauromorpha by
Pavanatto et al. (2018). M�ller (2021) named it and redescribed
it as a new taxon of theropod. Using M�ller and Garcia's pan-avian analysis, it emerged as a theropod based on the
anterior trochanter being separated from the shaft by a celft, but was
outside Neotheropoda. Unfortunately, M�ller's original 2020 preprint has no mention of
ZooBank. Thus
according to ICZN Article 8.5.3 (an electronic work must "be
registered in the Official Register of Zoological Nomenclature
(ZooBank) (see Article 78.2.4) and contain evidence in the work itself
that such registration has occurred"), "Erythrovenator jacuiensis"
M�ller, 2020 is a nomen nudum that was valid once published in April 2021.
References- Pavanatto, Pretto,
Kerber, M�ller, Da-Rosa and Dias-da-Silva, 2018. A new Upper Triassic
cynodont-bearing fossiliferous site from southern Brazil, with
taphonomic remarks and description of a new traversodontid taxon.
Journal of South American Earth Sciences. 88, 179-196.
M�ller, 2021 (online 2020). A new theropod dinosaur from a peculiar Late
Triassic assemblage of southern Brazil. Journal of South American Earth
Sciences. 107, 103026.
Nhandumirim Marsola, Bittencourt, Butler, Da Rosa, Say�o and Langer, 2019
= "Nhandumirim" Marsola, 2018
N. waldsangae Marsola, Bittencourt, Butler, Da Rosa, Say�o and Langer, 2019
= "Nhandumirim waldsangae" Marsola, 2018
Middle Carnian, Late Triassic
Cerro da Alemoa, Alemoa Member of Santa Maria Formation, Brazil
Holotype- (LPRP/USP 0651) (three year old juvenile) incomplete
posterior dorsal vertebra, two posterior dorsal centra, second sacral
centrum (15 mm), sacral centrum (14 mm), two sacral ribs, three
incomplete proximal caudal vertebrae, two incomplete mid caudal
vertebrae, two distal caudal vertebrae (one partial), chevron,
incomplete ilium, femur (120 mm), partial tibia, fibula, metatarsal II,
metatarsal IV, five pedal phalanges (one incomplete), three proximal
pedal unguals, fragments
Diagnosis- sharp longitudinal keels on ventral surface of proximal
caudal centra; brevis fossa projecting for less than three-quarters of
the length of ventral surface of postacetabular process; proximally
short dorsolateral trochanter that terminates well distal to level of
femoral head; distal tibia with mediolaterally extending tuberosity on
anterior surface, in addition to a tabular posterolateral flange;
conspicuous, anteromedially oriented semicircular articular facet on
distal fibula; straight metatarsal IV.
Comments- Discovered by April 2015, Marsola et al. (2015) first announced LPRP/USP 0651 as "a new
small-sized gracile dinosaur" recovered "as a basal saurischian
dinosaur, with no clear relationship to less inclusive groups. Yet
interestingly, its variable position in the different recovered
phylogenetic hypotheses accompanied that of Eoraptor lunensis,
suggesting a possible affinity to that taxon." Marsola's (2018) thesis
includes a chapter which is a pre-submission version of the eventual
description written October 2017, making that use of Nhandumirim
waldsangae a nomen nudum (ICZN Article 8.1.1). Marsola et al. (2019)
officially named and described the taxon, finding it sister to neotheropods
in Cabreira et al.'s dinosauromorph analysis and in a saurischian
polytomy with Tawa+Neotheropoda and sauropodomorphs in Nesbitt's archosaur matrix.
References- Marsola, Bittencourt, Da-Rosa and Langer, 2015. A small-sized
saurischian dinosaur from the Late Triassic Santa Maria Formation, southern
Brazil. Journal of Vertebrate Paleontology. Program and Abstracts 2015, 175.
Marsola, 2018. Triassic dinosauromorphs from southern Brazil and
biogeographic patterns for the origin of dinosaurs. PhD thesis,
Universidad de Sao Paulo. 199 pp.
Marsola, Bittencourt, Butler, Da Rosa, Say�o and Langer, 2019. A new
dinosaur with theropod affinities from the Late Triassic Santa Maria
Formation, south Brazil. Journal of Vertebrate Paleontology. e1531878.