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European Triassic theropods



Hi everyone.  I finally got some GAIA papers, including the all important Holtz theropod phylogeny.  Yes Tom, at last I can integrate your characters and have the best analysis ever!  Bwa ha ha, er, um, never mind.  The point of this post however is to inform all of you as to the results of Rauhut and Hungerbuhler's study of European Triassic theropods as seen in the following paper-
Rauhut and Hungerbuhler, 2000. A review of European Triassic theropods. Gaia 15, 75-88.
 
Avipes dillstedtianus
This is referred to probable Archosauria gen. et sp. indet., because there are no characters to distinguish it from various types of digitigrade archosaurs.  I'm not too sure about this, as I thought only ornithodirans had the digitigrade stance implied by Avipes' metatarsal gracility and arrangement.  But I'm not very knowledgable regarding non-dinosaurian archosaurs or Avipes, so I can't make an informed opinion.
 
Dolichosuchus cristatus
This has a large cnemial crest and fibular crest, showing it is theropod.  Rauhut and Hungerbuhler note close resemblence to Liliensternus and Dilophosaurus, suggesting it is probably a coelophysoid.
 
Halticosaurus longotarsus
Originally based on a dentary fragment, teeth, three cervicals, two dorsals, two sacrals, a caudal, a proximal humerus, ilial fragments, proximal femora and metatarsal II; only a cervical vertebra, dorsal centrum, fragmentary vertebral centrum, femora and metatarsal could be located.  The authors note the material is very poorly preserved and most is not identifiable as theropod.  As the holotype was found with Sellosaurus gracilis remains, some may be prosauropod.  The proximal femora show a spike-like lesser trochantor and downturned head, as in coelophysoids.  The authors therefore think some of the type may be coelophysoid, although they still believe it is indeterminate.  However, Welles (1984) finds that the femoral head is smaller and the anterior trochantor is lower than Liliensternus.  The greater trochantor is higher and less rounded, anterior trochantor located more laterally and fourth trochantor lower and more lateral than Dilophosaurus.  This suggests the taxon may not be indeterminate.
 
"Halticosaurus" orbitoangulatus
This one was a surprise.  The strongly anteriorly tapering antorbital fenestra, circular tooth cross section, longitudinal striations, and lack of serrations and carinae suggest this archosaur is a sphenosuchian crocodylomorph.  No theropod synapomorphies could be found.  Yet another ex-dinosaur that has to be removed from your lists. :-)
 
Liliensternus liliensterni
The syntype remains of this species are usually referred to two individuals.  However, the material was found disarticulated and may represent more than two individuals.  Because of this and the fact it is hard to separate the remains belonging to the various individuals, Rauhut and Hungerbuhler recommend retaining all of the material as the syntypes of Liliensternus (contra Welles 1984, who made the larger individual the syntype).  Because the neurocentral sutures are unfused and only two fused sacrals are present, the remains are probably juveniles or subadults.  Contra Rowe and Gauthier (1990), the pubis encloses a complete obturator foramen, not just a notch.  The authors accept Liliensternus as a coelophysoid.
 
Liliensternus airelensis
Although the authors believe this is a valid species, they think characters such as the presence of two pairs of cervical pleurocoels (versus one pair in L. liliensterni), may indicate this deserves a separate genus.
 
Procompsognathus triassicus
A detailed description of the reprepared skull is in progress by Chatterjee (pers. comm. to Rauhut, 1996), so the authors do not consider the skull.  They note that the slightly bowed pubis with rectangular apron and absence of a pubic foot in this specimen are symplesiomorphies, so do not help resolve relationships (contra Ostrom 1981, Sereno and Wold 1992).  They think the elongate dorsal vertebrae and triangular dorsal transverse processes may indicate ceratosaurian or coelophysoid affinities.  It is provisionally regarded as valid based on an elongate hindlimb (tib/fem 1.2, mtIII/fem .74).  I do not find this character convincing, as Podokesaurus has similar ratios (tib/fem 1.21, mtIII/fem .76) and Coelophysis can also have similar proportions (tib/fem 1.17, mtIII/fem .71).  Still, I feel there is a good possibility future work (such as Sereno's upcoming work on Segisaurus...) will provide valid synapomorphies.
 
Pterospondylus trielbae
This species has been associated and synonymized with Procompsognathus in the past based only on the elongate centrum.  The transverse processes are triangular, resembling Syntarsus more than Liliensternus and Dilophosaurus.  Thus, the authors suggest the taxon may be a coelophysid.
 
Saltopus elginensis
This specimen is very poorly preserved, being preserved mostly as imprints and goethite.  The impressions indicate only two sacral vertebrae (contra Huene 1910 and Norman 1990).  Also, the preacetabular process is short (contra Huene 1910) and there is a small pedal digit I.  I wrote about Saltopus here- http://www.cmnh.org/fun/dinosaur-archive/2000Sep/msg00051.html .  This new data invalidates the two dinosaurian characters I noted, as well as two of the three potential pterosaurian characters.  I suppose that leaves the possibility of a marasuchid, which is similar to the authors conclusion that it is a probable dinosauriform indet..
 
Syntarsus? sp.
Material- (BMNH PV RU P 77/1, RU P 76/1) posterior dorsal vertebrae, partial sacrum, pelvis, femur lacking distal end
The authors state it is extremely similar to Syntarsus in all features, although it are also very similar to Procompsognathus and may prove to be referrable to that genus.  I haven't even attempted to study the coelophysid group.  Much more work is neccessary to properly distinguish Coelophysis, Syntarsus, Eucoelophysis, Camposaurus and other such things.  Perhaps it would be best to refer this to Coelophysidae incertae sedis until it is studied in more depth.
 
Tanystrosuchus posthumus
The elongate prezygopophyses and ventral groove show this is theropod, but more precise relationships are hard to determine.  They place it as Theropoda indet..
 
Velocipes guerichi
The supposed theropod fibula is so poorly preserved, the authors cannot say that it is a fibula, let alone theropod.  They place it as Vertebrata indet..  Ouch!  At least let it be Reptilia or something! ;-)
 
Megalosaurus? cambrensis
The authors note that the three supposed derived characters shared with Megalosaurus are not valid.  The angular rostral margin is found in Liliensternus, Syntarsus and Sellosaurus for instance.  The separate interdental plates are found in Plateosaurus, Dilophosaurus and several other  theropods (although oddly enough, most have fused interdental plates or none at all).  The third character, "replacement teeth exposed at base between interdental plates", is correlated with separate interdental plates.  The authors find it agrees quite well with Liliensternus and Dilophosaurus, but refer it to Theropoda indet..  Again, Welles found several differences from Dilophosaurus, so I think we should wait for an in depth analysis to proclaim this specimen indeterminate.
 
Also, a theropod femoral fragment (Galton, 1985) is known from the Stubensandstein of Germany and some probable theropod teeth (Buffetaut and Wouters, 1986) are known from the Norian of France and Knollenmergel of Switzerland and Germany.  Megalosaurus? cloacinus, M? obtusus and "Plateosaurus" ornatus were not considered, as they are based on teeth.
 
That's it for now.  Maybe I'll write about Iliokelesia soon, or new details from Holtz's analysis.  But that will interfere with my Chuandongocoelurus work... :-)
 
Mickey Mortimer