Talk:Tarbosaurus

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A request has been made for this article to be copyedited by the League of Copyeditors. The progress of its reviewers is recorded below. The League is always in need of editors with a good grasp of English to review articles. Visit the Project page if you are interested in helping. Add comments Copyedited by Finetooth (talk) – 00:15, 30 January 2008 (UTC)

Contents 1 Evidence from morphological characters that Tarbosaurus is not congeneric with Tyrannosaurus 2 Is it confirmed that Tarbosaurus (Tyranowaurus) Battaar is a relative or even an ancestor of T,.Rex? 3 Review of Mongolian tyrannosaurs 4 Relationship of Shanshanosaurus 5 Relationships of the genera nitpickery 6 Looks great, Sheep 7 "Fingers": 2, 3, or what? 8 GA Review

[edit] Evidence from morphological characters that Tarbosaurus is not congeneric with Tyrannosaurus

Hurum and Sabath (2003) demonstrated Tarbosaurus is not a species of Tyrannosaurus. This was based on the skull of Tarbosaurus being more primitive than that of Tyrannosaurus. Currie, Hurum, and Sabath (2003) conducted a cladistic analysis of the family Tyrannosauridae, concluding that Tarbosaurus is closer to Alioramus than to Tyrannosaurus. The conclusion made by Hurum and Sabath (2003) is based on re-examinations of the skulls of Tarbosaurus and Tyrannosaurus.

Currie, P.J., Hurum, J.H., and Sabath, K. 2003. Skull structure and evolution in tyrannosaurid dinosaurs. Acta Palaeontologica Polonica 48 (2): 227–234.

Hurum, J. H. and Sabath, K. 2003. Giant theropod dinosaurs from Asia and North America: Skulls of Tarbosaurus bataar and Tyrannosaurus rex compared. Acta Palaeontologica Polonica 48 (2), 161-190

Did they show that T. bataar is closer to Alioramus than T. rex using cladistic analysis, or was this just a genericomertical exercise? If is was cladistic, what makes it superior to other analysis? John.Conway 16:02, 9 October 2006 (UTC)

Oops, just read the paper -- still, I'm not sure this is the final word on the subject, it is one analysis that disagrees with a bunch of other (and excludes post-cranial data). John.Conway 17:25, 9 October 2006 (UTC)

[edit] Is it confirmed that Tarbosaurus (Tyranowaurus) Battaar is a relative or even an ancestor of T,.Rex?

I need this info for my essay; plz someone help me —The preceding unsigned comment was added by Didigo10 (talk • contribs) 04:36, 1 January 2007 (UTC).

[edit] Review of Mongolian tyrannosaurs

Olshevsky (1995) recognizes three species of tyrannosaurids from Mongolia: Tarbosaurus efremovi Maleev, 1955, Jenghizkhan bataar (Maleev, 1955) (Gorgosaurus lancinator Maleev, 1955 is a junior synonym), and Maleevosaurus novojilovi (Maleev, 1955). The diagnosis for Jenghizkhan is given in Olshevsky (1995): The genus Jenghizkhan differs from other members of the paratribe Tarbosaurini in its larger size (overall adult length about 14 meters) and its massively constructed, rugose vertical skull elements, namely, the postorbital-jugal bar and lacrimal-jugal bar. In Tarbosaurus efremovi these vertical elements are relatively slender, with quite smooth external surfaces. In Jenghizkhan, the lacrimal and postorbital meet above the orbit to create a continuous circumorbital flange from approximately the middle of the vertical ramus of the lacrimal around to the suborbital tuberosity ("postorbital bar") on the vertical ramus of the postorbital. The frontal is thereby excluded from the orbital rim, although a notch may be present at the dorsal apex where the lacrimal rugosity contacts the postorbital rugosity. In Tarbosaurus efremovi and most other tyrannosaurids, the frontal remains part of the orbital rim as a well-defined notch or discontinuity in the circumorbital surface, separating the lacrimal from the postorbital. These characters are probably not age-related, since they are present in the holotype juvenile skull of Gorgosaurus lancinator.

Once a paper describing variation within Mongolian tyrannosaurids is published, Olshevsky's proposed classification may become accepted. But Olshevsky himself continues defending the validity of Jenghizkhan and Maleevosaurus from Tarbosaurus.

Maleev, E.A. 1955a. Giant carnivorous dinosaurs of Mongolia [in Russian]. Doklady Akademii Nauk SSSR 104: 634–637.

Maleev, E.A. 1955b. New carnivorous dinosaurs from the Upper Cretaceous of Mongolia [in Russian]. Doklady Akademii Nauk SSSR 104: 779–782.

Olshevsky, G. 1995. The origin and evolution of the tyrannosaurids [in Japanese]. Kyoryugaku Saizensen (Dino Frontline) 9: 92–119; 10: 75–99.

I'm not sure that anyone other than Olshevsky has accepted the name Jenghizkhan though. Cas Liber 01:00, 14 January 2007 (UTC)

He doesn't even accept it any more. J. Spencer 01:28, 14 January 2007 (UTC)

[edit] Relationship of Shanshanosaurus

Carr (2005) found Shanshanosaurus to be the sister taxon of a clade containing Tarbosaurus and Tyrannosaurus. This may mean that the taxonomic status of Shanshanosaurus needs reconsideration again (if postcranial remains are found at the type locality of Shanshanosaurus).

Carr, 2005. Phylogeny of Tyrannosauroidea (Dinosauria: Coelurosauria) with special reference to North American forms. Unpublished PhD dissertation. University of Toronto. 1170 pp.

[edit] Relationships of the genera nitpickery

The additions look great, but there is a problem with the sentence "Whether or not Tarbosaurus is synonymous with Tyrannosaurus, the two are usually considered to be closely related." If Tarbosaurus is not synonymous with Tyrannosaurus, the two genera are closely related. However, if Tarbosaurus is synonymous with Tyrannosaurus, they aren't related genera: they're the same genera. Only the two species (Tyrannosaurus rex and Tyrannosaurus bataar) would be related. I thought of rewording this myself, but couldn't come up with a rewording that didn't sound cluttered or incomprehensible.

Attempts at rewording include:

1. "If Tarbosaurus is not actually synonymous with Tyrannosaurus, the two are usually considered to be closely related." (Workable, but clumsy)
2. "If Tarbosaurus is synonymous with Tyrannosaurus, the two species T. rex and T bataar would be closely related." (Which sort of sounds silly because it's so obvious).
3. "If Tarbosaurus is synonymous with Tyrannosaurus, it represents a second species of Tyrannosaurus, called Tyrannosaurus bataar. If it is not synonymous, then the two genera are closely related." (Possibly overly long)

Firsfron of Ronchester 23:03, 24 November 2007 (UTC)

How about "Even if Tarbosaurus is not synonymous with Tyrannosaurus, the two are usually considered to be closely related." Sheep81 (talk) 23:11, 24 November 2007 (UTC)

Yeah, something like that. Firsfron of Ronchester 23:12, 24 November 2007 (UTC)

[edit] Looks great, Sheep

Really does. :) There is a broken link: Ref #26, Brochu, Christopher A. (2000). "[0001%3AADREFT2.0.CO%3B2&ct=1 A digitally-rendered endocast for Tyrannosaurus rex]". Journal of Vertebrate Paleontology 20 (1): 1-6. Firsfron of Ronchester 01:23, 8 December 2007 (UTC)

those stupid URLs never work from that site. I've replaced it with a not-quite-as-good link. Sheep81 (talk) 01:31, 8 December 2007 (UTC)

[edit] "Fingers": 2, 3, or what?

"tyrannosaurids, a group already renowned for their disproportionately tiny, two-fingered forelimbs."
- From Tyrannosauridae: "It was once thought that the tyrannosaurs had only two fingers on each hand, but paleontologists have since discovered that T. rex had three (two primary fingers and one small vestigial finger), raising the probability of the fact that the other tyrannosaurs had them."
-- What do we want to do with this? Okay as it stands in Tarbosaurus, or modify? -- Writtenonsand (talk) 01:24, 31 December 2007 (UTC)

This is what's tricky about sticking to published sources on cutting edge topics. Yes, I'm sure if T. rex, the most derived tyrannosaur, retained a 3rd finger, then all of them probably did. However, there's no direct evidence of this and the logical answer has not actually been published, so should we mention it here? Wouldn't that be OR? Maybe the best solution right now is just remove the reference to two-fingered hands completely. Dinoguy2 (talk) 01:30, 31 December 2007 (UTC)

I don't think that it's a big deal. The Third Metacarpal, which is apparently all that Rexie really had, has been known for a while in several other tyrannosaurids. To partially repost from Talk:Tyrannosaurus:

"The Illustrated Encyclopedia of Dinosaurs (1985), p. 71, the second page of tyrannosaur skeletal illustrations, shows a hand of Tarbosaurus with a 3rd metacarpal. Similarly, if you go to the first Dinosauria (1990, p. 182 in the paperback edition), both Tarbosaurus and Gorgosaurus (then Albertosaurus libratus) have 3rd metacarpals. In the 2nd edition (2004), Daspletosaurus and Albertosaurus proper are also mentioned as having them, and it is assumed that Tyrannosaurus had one as well (p. 124). Finally, and to seal my required killjoy moment of the day, "third digit" may be technically accurate, but it's not a finger in the sense that most people are used to dealing with, and it's not like Tyrannosaurus really had Allosaurus hands; it had two "finger" fingers and an inanimate bony rod per hand." J. Spencer (talk) 01:58, 31 December 2007 (UTC)

I'm going to rewrite Tyrannosauridae in the style of Tyrannosauroidea very soon. In fact I'm already working on it. So this won't be an issue anymore. Sheep81 (talk) 03:54, 31 December 2007 (UTC)

Sounds good. " it's not a finger in the sense that most people are used to dealing with" True, but the hands of alvarezsaurs are not really "hands" in the sense people are used to dealing with--they're still technically hands... how do the other two recently discovered "digits" of alvarezsaurs compare with the third digit of tyrannosaurids? Seems to be a similar situation of a group thought to have a unique digit count found to have the standard theropod three, but with some highly modified. Dinoguy2 (talk) 04:10, 31 December 2007 (UTC)

This may be evidence that coelurosaurian theropods came up with "flipping the bird", and it was so adaptive that an odd number of digits greater than 1 per hand was retained even where having fewer than three might have otherwise been useful. J. Spencer (talk) 04:34, 31 December 2007 (UTC)

"This may be evidence that coelurosaurian theropods came up with 'flipping the bird'" -- A perfect example of how dangerous critters tend to come up with elaborate display mechanisms to avoid mauling each other unneccesarily.  :-) -- Writtenonsand (talk) 19:23, 1 January 2008 (UTC)

[edit] GA Review

This article is well-written, well-organized into clear and concise sections, and easy to understand. It meets the citation requirements for GAs. It also appears to be complete, and contains all of the important elements needed to cover the topic (anatomical description, biology, ecology, discovery). The illustrations all have appropriate copyright tags and go well with the text in illustrating the topic. I believe that this article meets all of the Good Article criteria, and it will be listed. It's probably not far from WP:FA, either. Though I would recommend a good copyedit, to clean up any minor issues with grammar, style, and prose. It might also be good to seek an A-class review with WP:DINO, or WP:PR, to make sure all of the details are thoroughly covered (though I think the completeness aspect is good enough for GA). Cheers! Dr. Cash (talk) 16:38, 2 January 2008 (UTC)