Largest dinosaurs of the Triassic?

[Deleted]

What are they? Including ichnotaxa and fragmentary obscure specimens.

Largest ornithischian?
Largest Sauropodomorph?
Largest theropod?

While at it, get the scientific literature here if you can find it.

[theropod]

The largest (known) theropod is probably Eubrontes isp. with large footprints reaching a lenght of 43cm and a width of 39cm (Silva et al. 2012). It has been estimated at 2.1m at the hip and 8m long or approximately the size of Allosaurus.

Silva, Rafael C.; Barboni, Ronaldo; Dutra, Tânia; Godoy, Michel M.; Binotto Raquel Barros: Footprints of large theropod dinosaurs and implications on the age of Triassic biotas from Southern Brazil. Journal of South American Earth Sciences, vol. 39 (2012); pp. 16-23:
www.cprm.gov.br/publique/media/Art_footprints_silva.pdf

In terms of what’s known from skeletal fossils, it’s probably a contest between Herrerasaurus (probably only max size), Liliensternus and Zupaysaurus (and maybe Gojrasaurus, if it’s a valid taxon).
Mortimer, Michael (2014): (The Theropod Database:) Coelophysoidea. archosaur.us/theropoddatabase/Coelophysoidea.htm Accessed 24.09.2016
Mortimer, Michael (2014): (The Theropod Database:) Non-theropods. archosaur.us/theropoddatabase/Non-theropods.htm Accessed 24.09.2018


In Sauropodomorpha, my bet is on one of the big South American or African "prosauropods" or basal sauropods (Melanorosaurus, Riojasaurus or Antetonitrus maybe, but I haven’t had time to educate myself sufficiently on that matter).

No idea about ornithischians, there weren’t too many around but it still feels deeply disturbing to consider something like Pisanosaurus or Eocursor the biggest of anything.

[blaze]

Camelotia borealis from southern England, appears to be a melanosaurus-like sauropodomorph with a 1008mm long femur, it might have been 10m long, femur circumference of 340mm, higher than either the humerus or femur circumference in a 3.5 tonne Asian elephant (Campione and Evans 2012 supplemental).

I don't think Liliensternus, Zupaysaurus and Gojrasaurus quite compete even against "classic" 4m Herrerasaurus yes, they are estimated to be longer, but limb bones and skull length are similar between them.

Liliensternus is the smallest, femur, tibia and skull length of 424mm, 409mm (*) and 395mm respectively, though it is a subadult. Femur circumference is 110mm.

Zupaysaurus and Gojirasaurus are next at about the same size, the skull of the former is 450mm (though this is debatable *) which based on Liliensternus suggests a femur and tibia 483mm and 473mm long respectively, the later being comparable to that of Gojirasaurus (469mm). Estimated femur circumference would be 125mm.

For comparison, the type of Herrerasaurus has a 482mm femur and a 415mm tibia (*), the circumference of the femur being 170mm, through cross-scaling using the measurements in the theropod database I estimate an skull ~400mm long for this specimen. So similar limb and skull lengths but way more robust and definitely heavier, then we have to remember that we have larger individuals than this and not only the "Frenguellisaurus" specimen.

Using the equation in Campione et al (2014) to estimate theropod mass we get this:

Liliensternus: 87kg
Zupaysaurus and Gojirasaurus: ~124kg
Herrerasaurus type: 289kg
Herrerasaurus max: ~729kg

(*) Benson et al. (2014) supplemental

[stomatopod]

Didnt the guys at SVPOW mention a Diplodocus sized Sauropodomorph? Or was that from the Jurassic?
And I miss the old Alwalkeria.

[Deleted]

Sept 25, 2014 7:09:23 GMT 5 blaze said:

Camelotia borealis from southern England, appears to be a melanosaurus-like sauropodomorph with a 1008mm long femur, it might have been 10m long, femur circumference of 340mm, higher than either the humerus or femur circumference in a 3.5 tonne Asian elephant (Campione and Evans 2012 supplemental).

I don't think Liliensternus, Zupaysaurus and Gojrasaurus quite compete even against "classic" 4m Herrerasaurus yes, they are estimated to be longer, but limb bones and skull length are similar between them.

Liliensternus is the smallest, femur, tibia and skull length of 424mm, 409mm (*) and 395mm respectively, though it is a subadult. Femur circumference is 110mm.

Zupaysaurus and Gojirasaurus are next at about the same size, the skull of the former is 450mm (though this is debatable *) which based on Liliensternus suggests a femur and tibia 483mm and 473mm long respectively, the later being comparable to that of Gojirasaurus (469mm). Estimated femur circumference would be 125mm.

For comparison, the type of Herrerasaurus has a 482mm femur and a 415mm tibia (*), the circumference of the femur being 170mm, through cross-scaling using the measurements in the theropod database I estimate an skull ~400mm long for this specimen. So similar limb and skull lengths but way more robust and definitely heavier, then we have to remember that we have larger individuals than this and not only the "Frenguellisaurus" specimen.

Using the equation in Campione et al (2014) to estimate theropod mass we get this:

Liliensternus: 87kg
Zupaysaurus and Gojirasaurus: ~124kg
Herrerasaurus type: 289kg
Herrerasaurus max: ~729kg

(*) Benson et al. (2014) supplemental

Ok, so we have 3+ tonne sauropodomorphs and 700+ kilogram theropods roaming around in the Triassic.

That sure destroys the belief that Triassic dinosaurs are all small(they're commonly depicted as runts, Plateosaurus from WWD being the only exception I know of).

Btw, can you send me the papers you cited(aside from the Benson et al. 2014 one, I have that one). Email address is [e-mail]

__

theropod: According to the paper, the original footprint, which would have reflected basically the size of the foot according to Fig. 4 of the paper(actually the foot seems to be a bit longer then the estimated size of the original footprint)would have been longer than the preserved footprint. If the preserved portion of FSSL-02 is ~43 centimeters long, the original foot print would be roughly ~46.78 centimeters long based on the Fig. 4 diagram, which, using their formula, results in a hip height of ~2.26 meters.

I'm not sure why they used carnosaurs to stand in for Grallator and Eubrontes in their size comparison, though, when Tetanurae wasn't known to even exist at the time.

__

stomatopod: What old Alwalkeria? It's a ~50-centimeter basal saurischian(formerly classified as a basal theropod) as far as I know.

[creature386]

So, later triassic theropods were smaller than the older ones (Herrerasaurus)? Does this mean that the Carnian-Norian extinction hit dinosaurs harder than expected? Even though this only seems to apply for theropods. I wonder who was able to threaten an adult Plateosaurus.

[blaze]

Maybe is a sampling issue? What could there be to hunt them? rauisuchians were already gone by the latest Triassic

@brolyeuphyfusion
With the exception of the measurements I took from Benson et al, I used the measurements in the theropod database so there's not really any paper to share but I'll try to find the description papers of the big coelophysoids, or are you interested in the Herrerasaurus papers?

[Deleted]

Sept 25, 2014 19:42:47 GMT 5 blaze said:

Maybe is a sampling issue? What could there be to hunt them? rauisuchians were already gone by the latest Triassic

@brolyeuphyfusion
With the exception of the measurements I took from Benson et al, I used the measurements in the theropod database so there's not really any paper to share but I'll try to find the description papers of the big coelophysoids, or are you interested in the Herrerasaurus papers?

The Camelotia one, and the ones of the big coelophysids if you can find them. And yes, the Herrerasaurus ones too.

[blaze]

We've found our winner, thanks for the hint stomatopod

A Diplodocus-sized bipedal basal sauropodomorph from the Late Triassic of South Africa
SVPCA Platform Presentation, 2011 (Lyme Regis)

Mathew J Wedel & Adam M Yates

A partial skeleton of a basal sauropodomorph from the Lower Elliot Formation (mid to late Norian) of South Africa represents an animal of unprecedented size for that place and time.

Available material includes dorsal and caudal vertebrae, a dorsal rib, a chevron, an ulna, and a pedal ungual, with additional elements under preparation. All of the elements are exceptionally large, on average 1.9 times the linear size of the largest individual of the contemporary Aardonyx. Aardonyx was previously the largest known non-sauropod from the Lower Elliott Formation, with a femur length of up to ~800 mm. Cross-scaling from other basal sauropodomorphs suggests a femur length of ~1500 mm and a mass of 10-15 metric tons for the giant Elliot form. These estimates are comparable to the femur length (1540 mm) and estimated mass of CM 84/94, the holotype of Diplodocus carnegii. The ulna is unusually short and robust, 20% shorter than expected based on the other elements, and its morphology suggests that, like some other large basal sauropodomorphs, the giant Elliot form was an obligate biped. This is opposite to the trend of forelimb elongation in quadrupedal basal sauropods.

The giant Elliot form represents the largest known non-sauropod sauropodomorph and one of the largest bipedal animals of all time. It demonstrates that basal sauropodomorphs achieved very large body size despite lacking most of the presumed key innovations of sauropods, such as quadrupedal stance, columnar limbs, and extensive skeletal pneumaticity.

@brolyeuphyfusion
I don't have the Camelotia and big coelophysoids right now but I'll search for them, I'll send you the herrerasaurus ones I have.

[Deleted]

Sept 25, 2014 20:03:00 GMT 5 blaze said:

We've found our winner, thanks for the hint stomatopod

A Diplodocus-sized bipedal basal sauropodomorph from the Late Triassic of South Africa
SVPCA Platform Presentation, 2011 (Lyme Regis)

Mathew J Wedel & Adam M Yates

A partial skeleton of a basal sauropodomorph from the Lower Elliot Formation (mid to late Norian) of South Africa represents an animal of unprecedented size for that place and time.

Available material includes dorsal and caudal vertebrae, a dorsal rib, a chevron, an ulna, and a pedal ungual, with additional elements under preparation. All of the elements are exceptionally large, on average 1.9 times the linear size of the largest individual of the contemporary Aardonyx. Aardonyx was previously the largest known non-sauropod from the Lower Elliott Formation, with a femur length of up to ~800 mm. Cross-scaling from other basal sauropodomorphs suggests a femur length of ~1500 mm and a mass of 10-15 metric tons for the giant Elliot form. These estimates are comparable to the femur length (1540 mm) and estimated mass of CM 84/94, the holotype of Diplodocus carnegii. The ulna is unusually short and robust, 20% shorter than expected based on the other elements, and its morphology suggests that, like some other large basal sauropodomorphs, the giant Elliot form was an obligate biped. This is opposite to the trend of forelimb elongation in quadrupedal basal sauropods.

The giant Elliot form represents the largest known non-sauropod sauropodomorph and one of the largest bipedal animals of all time. It demonstrates that basal sauropodomorphs achieved very large body size despite lacking most of the presumed key innovations of sauropods, such as quadrupedal stance, columnar limbs, and extensive skeletal pneumaticity.

@brolyeuphyfusion
I don't have the Camelotia and big coelophysoids right now but I'll search for them, I'll send you the herrerasaurus ones I have.

O..M...G...

This isn't only the largest Triassic dinosaur, it's basically the largest known Triassic land animal and the largest known biped!

Btw, what's the name of the paper(supplementary) which you got the Camelotia measurements from? Maybe I can have a try on finding it at Google Scholar.

And thanks!

[blaze]

The exact measurements were from the supplemental in Benson et al 2014 but I came to know about it thanks to a blog post by Adam Yates.
here, he has it at second place but I thought its dimensions were more reliable than the estimates for "Yunnanosaurus" youngi which Greg Paul estimate as smaller.

Here's a paper that mentions Camelotia and describes two giant shafts from the Triassic of England. I'm still tracking the exact citation of the papers that deal with Camelotia.

Btw, could you properly attribute the size charts on carnivora that you made with Hartman's skeletals? since you left around the time he made that request yours are the only ones that were left unchanged.

edit: Sanders et al (2011) writes this about large Triassic theropods:

That theropods may also have evolved rapidly to very large size, is suggested by footprints left by Allosaurus-sized theropods in the Late Triassic (Thulborn, 2003; Lucas et al., 2006) and the remains of an Allosaurus-sized coelophysoid from the Late Triassic of Bavaria, Germany (Rauhut, personal observation).

[theropod]

creature386: The Eubrontes ichnites I already mentioned are considered to be Norian-Raetian in age. They are from Brazil, but Eubrontes is rather widespread (even though not consistently this size), and similar predators likely existed in Europe. I think an Allosaurus-sized coelophysoid may well have been able to bring down a Plateosaurus.

It appears the limits of Coelophysoid size are not well-known yet. Given that those footprints are Coelophysoids, that would indicate them reaching respectable sizes. Furtermore there is that Hettangian 54cm footprint from Poland (Gierlinski et al. 2001), for which the most likely contender is also a Coelophysoid.

That Diplodocus-sized sauropodomorph sounds incredible! I wouldn’t have thought that there was something that huge on land that early.

[creature386]

Looks like Allosaurus vs Diplodocus (size-wise) already happened in the Triassic.

[spinodontosaurus]

My bet would have been Plateosaurus were it not for that Diplodocus-sized sauropodomorph. The largest known Plateosaurus femur is around a meter long. Based on 3D modelling in Mallison (2010), Gunga et al., (2007), and a GDI estimate by Matt Wedel over on SV-POW for an individual with a 60 cm femur, the 100 cm femur could have come from an animal over 3 tonnes in weight.

Now this is something that in the past impressed me considering Plateosaurus is quite an early dinosaur, but that basal sauropodomorph from South Africa blows it out the water. Very impressive.

[Deleted]

Sept 25, 2014 23:14:01 GMT 5 blaze said:

Btw, could you properly attribute the size charts on carnivora that you made with Hartman's skeletals? since you left around the time he made that request yours are the only ones that were left unchanged. 

Ok, I'll do. I don't even have to go back to CF, they're all uploaded to imgur so I could just edit them there.