All posts by Birdman04

Predominantly fish eater that barely went after things bigger than it's head vs a sauropod hunter, very fair

Hasn't been for several years

Somewhat doubtful

Closest to tyrannosauroids

Fragilis very likely

I've just now fully read nighthawk's first post that caused all of this, I'm quite frankly confused by the level of detail and despair it devolved into.

Sauro is still very dubious even if the holotype specimen is allosauroid, the chevrons and atlas got snatched away (meaning much less automorphies to use to defend it's validity), now even if it's distinct it's probably gonna end up as Allosaurus maximus at best, barely defendable as a separate species let alone a whole genus.

Lmfaooo

Dumb asf, the FSAC specimen (while possibly not being spino) is almost certainly not a chimera (except for maybe the sacrals)

The only other theropod that could realistically rival tyrannosaurus in coolness is Allosaurus, asides that other large theropods simply don't compare in sample size, biology and naming

"There is. Here: Postcranial bones of a juvenile Iguanodon and Lepidotes scales found in the ribcage of the holotype of Baryonyx, as well as a tooth of a spinosaurid embedded within a pterosaur cervical vertebra and the association of Iberospinus material with Iguanodon from Portugal (O.M. pers. obs.), support the fact that these tetanurans were opportunistic animals feeding on fish, ornithopods, and pterosaurs.

You cannot explain all of the aforementioned exclusively with Scavenging."

Anything that directly indicates predation? Maybe, but again not confirmed, and that wasn't my original point, my original point was do we have anything that indicates spinosaurids were taking medium sized prey, and all the above is, again, unconfirmed stuff, the original description for baryonyx even directly acknowledges there is no way to determine if juvenile iguanodontid was scavenged or predated:

The spinosaurid that ate a pterosaur isn't too impressive, since pterosaurs are very lightweight animals (obviously) and such would not have "medium sized" at all.

However, if you're trying to argue about spinosaurids being more generalist than I'm saying (as in not exclusively feeding on fish) sure, I'll accept these arguments.

"Absolutely One sided. This is a direct excuse for being defensive for some theropods meanwhile being blatantly dismissive for others.

Also there are other stress related studies :"

You linked the same study twice, but anyways, I did reference this paper when I said crocs outperform spinosaurids in stress tests, and admittingly I should have phrased it better, when the skulls were scaled to the same size, baryonyx preformed better than the gharial and west african croc, but was surpassed in stress resistance by the gator (though the authors used the skull of a relatively young one), but for spinosaurus (although the rostrum used was pretty gracile) it was comparable to the gharial and the west african croc used, if not worse in some cases.

"Also it is Not easily ignora-able that Spinosaurus having more biteforce compared to all aforementioned:

Xuanhanosaurus, Ceratosaurus, Majungasaurus, Metriacanthosaurus; Sinraptor, Megalosaurus, Rajasaurus, Aucasaurus, Megaraptor, Chilantaisaurus, Deltadromeus, Rapator, Raptorex...etc."

Most of these don't even have actual bite force estimates (especially since some lack skull material entirely)

"Here: [ They also reported that the possible Portuguese Iberospinus - formerly seen as Baryonyx - fossils were found associated with isolated Iguanodon teeth, and listed it along with other such associations as support for opportunistic feeding behaviour in spinosaurs ]

So we have both england Baryonyx with iguanadontid and Iberispinis with iguanadontids."

So no actual fossils indicating direct evidence of predation or even scavenging, just a possible assumption based on fossils getting clumped together. The problem I have here is that you're trying to say iberospinus was preying on iguanodontids, yet the actual evidence you provided seems scant at best. Saying these were scavenged is one thing, but to call it predation is a whole another level.

"Odd. We also have various bite and stress studies. That show Spinosaurus itself had a biteforce and withstanding better than several medium to large sized theropods such as Allosaurus; Torvosaurus; Saurophaganax; Metricisaurus; chillantisaurus...etc."

Not too surprising, the latter theropods seem much more adapted for macropredation than spinosaurus, and are also significantly smaller. A 2t allosaurus's skull is not going to withstand stresses as well as a much larger 8t spinosaurus's skull, but when scaled up to the same size, vise versa.

The same as Bruhathkayosaurus

Dubious lost fragment that realistically should be ignored. (I don't like it)

Angaturama is literally just a snout tip (meaning any kind of fossils being referred to it is dubious at best), what kind of fossils are we talking about that proves that taxon (if valid) were taking terrestrial prey?

“Baryonyx and Iberospinus shown to consume Iguanadontids.”

Iberospinus where? The initial description of the type in 2011 and 2022 said nothing indicating it had eaten an iguanodontid.

Baryonyx is iffy, sure, the type specimen has the remains of a young iguanodontid in its stomach, but is there anything that proves it explicitly preyed on said iguanodontid? Otherwise it could easily just be scavenged.

Siamosaurus (being a dubious tooth taxon ofc), again, how can we be sure it was preying on sauropods; otherwise it can again easily be chalked up to just scavenging.

“Spinosaurus subadult Carcharodontosaurus. So... its pretty clear that 'medium' sized is not a restriction either :)”.

Based on what? If you’re referring to that vert that got sold off to a private collection, that one is highly dubious, if not outright fabricated because:

1. Private collection specimens are usually not reliable (Morocco especially since a lot of faked fossils come from there)

2. The “bite marks” realistically could have been inflicted by any theropod / crocodilian, there’s nothing that proves a spinosaurid, let alone Spinosaurus attacked this carcharodontosaurus (it it actually is carcharodontosaurus)

3. The tooth crown is facing backwards, totally not suspicious at all

4. The preservation of the tooth is completely different to the catch vert, only fueling suspicion that it was fabricated

5. Again, how can you be sure this is a predation event of some kind? (seemingly no signs of the vert healing at all)

“Additionally; this Study actually validates that Spinosaurinae ( Spinosaurus included and closest relatives to it ) mouth shape is far much more similar and reminiscent of Actual - generalist / apex predatory crocodiles of today. Extremelly unlike gharial ( which to be really honest gharials are the most Extreme amongst all known crocodilians today. All elongated snouted crocs are and were predatory from orinoco crocs to australian freshwater crocs to slender snouted crocs to false malay gharials )”

Sure, the tooth alveoli are comparable in robustness to crocodilians, but spinosaurs also get outperformed by crocs in stress tests (at a similar size). The enlarged alveoli sounds more like an adaptation to grip large fish and small prey more effectively and makes more sense to me than to be used in taking relatively larger game (as compensation for their rather stress skulls). Sure that spinosaurus feeding style is unlike that of any theropod, but i still severely doubt a 8t spinosaurus is preying on something like a 5t iguanodon, a 5t sucho preying on something like a 3t nigersaurus? Maybe, still doubt it be a frequent occurrence though.

I could see baryonychinae being possible generalists sure (given their more basal brain structure and seemingly more terrestrial habits, at least for some taxa), spinosaurines though (especially spinosaurus)? Nah. I still see them as primarily piscivorous with them occasionally taking small prey.

How large is "medium sized prey" exactly?

A predominantly piscivorous theropod occasionally exhibiting generalistic behavior, nothing too special really.

Not saying it's bad to like fragmentary taxa, but we barely know what they look like, and usually when we do find more complete specimens of said taxa there's a chance the animal can look completely different to how it was reconstructed before

Just saying