The Lake Wanderer

Paleontology nerd who likes pterosaurs

[jurassicsunsets]

out of curiosity, has evidence for non-carnivorous pterosaurs ever been found?

Yep, tapejarids were probably frugivorous!

[jurassicsunsets]

For the record, vultures only have bald heads as a thermoreuglatory mechanism. It doesn't have jack to do with them being scavengers.

Yep.

[lacusovagus]

It probably does have to do with scavenging, actually - being able to thermoregulate by simply covering or uncovering the head saves energy. Saving energy is valuable for an obligate scavenger that doesn’t have as reliable a food source, and vultures have multiple other adaptations to do so (e.g. gliding over powered flight). This’d explain why two lineages of obligate scavenging Accipitrimorphs evolved bald heads independently.

Of note, the palm-nut vulture, which isn’t a scavenger, and lammergeier, which focuses on highly nutritious bone marrow and does sometimes attack living animals, have more feathery heads.

[jurassicsunsets]

Is there evidence for pterosaur rookeries or is it a palaeo doc meme?

I don’t believe there is any evidence of them; I’ll double check in Witton’s book and get back, though!

[lacusovagus]

Actually there is evidence! Hamipterus is known from a bonebed with many sexually dimorphic adults and five unhatched eggs - this was interpreted as possible colonial nesting in the description. 

[a-dinosaur-a-day]

I just want to know and i hope this doesn't bother you. How can scientist identify a genus just from a part of the jaw?

Well, you see, the awkward thing is, is that, I’m a biologist, and uh, to be honest, I’m not entirely sure, because obviously, Paleontologists can’t use the biological species concept, in that, they don’t know which of these things they’re finding did the do with each other, so, awkwardly enough, it’s fairly arbitrary, where they draw genus and species lines, so, uh, that?

[lacusovagus]

Paleontologists use the morphological species concept. With fossils, morphology is all there is. Specifically for Unescoceratops, it was considered to be a specimen of Leptoceratops for a while until further study revealed the lower jaw differed from all other Leptoceratopsids. The morphology of the holotype lower jaw of Unescoceratops koppelhusae can be distinguished as distinct from all other known Leptoceratopsids, in ways likely not due to individual variation, and thus under the morphological species concept U. koppelhusae is a distinct species.

Now genera are largely arbitrary, and that’s a different story.

[tepuitrouble]

#Pterosaur Ptuesday Alanqa saharica! #paleoart #sciart #illustration

Alanqa is a genus of late Cretaceous Azhdarchid pterosaur known from southern Morocco’s Kem Kem beds.

The Kem Kem beds represent Africa’s most diverse pterosaur faunal assemblage, however most of the fossil material is poorly preserved and consist of isolated bones or bone fragments not diagnostic at the genus level.

[src]

Alanqa is known from fragmentary vertebrae, jaw and rostrum fragments from two individuals.  The first set of fossils was described in 2010 and a second set from a larger individual was described in 2015. 

The jaws are elongated and lance-shaped, as is typical of Azhdarchids, but also feature bony ridges that may have served as anchor points for soft tissue, or as surfaces for crushing shellfish.

[src]

The geology of the Kem Kem beds isn’t well understood, but seem to represent a complex fluvial (river) system, featuring turtles, crocodylimorphs and dinosaurs such as Spinosaurus and Carcharodontosaurus.

Sources

[1] [2] [3]

[lacusovagus]

Is it possible for any aquatic reptile to develop an epaulette shark-like strategy?

I can’t think of any off the top of my head which show evidence for it, but I wouldn’t be surprised if a marine reptile evolved a similar locomotive strategy.

[lacusovagus]

Which specific fossil formations would you like to add in your hypothetical documentary?

Well-known ones. Potential localities include:

Burgess Shale

Fezouata Formation

Cleveland Shale

Gogo Formation

Mazon Creek Fossil Beds

Karoo Supergroup

Ischigualasto Formation

Tiaojishan Formation

Morrison Formation

Solnhofen Plattenkalk

Either the Yixian or Jiufotang Formation

Santana Formation

Niobrara Formation

Nemegt Formation

Hell Creek Formation

Ellesmere Island

Messel Pit

Riversleigh

Pisco Formation

La Brea

[lacusovagus]

If you had the power to create your own documentary on Prehistoric Life, what would be your ideal documentary?

For starters, more than six episodes, and each may be more than a half hour long. It’d be filmed like Walking with Dinosaurs, as a nature documentary with prehistoric life, with either interjections (a la Planet Dinosaur), a section at the end, or ancillary videos (like what was planned for Dinosaur Revolution) explaining the science behind it and the “greater picture” in the history of life (the K-Pg extinction would only be brought up in one of these). Visually it’d be a blend of real and digital; animated animals would be supplemented with puppetry and animatronics, and environments would be a blend of filmed locations and digital backgrounds and elements (e.g. compositing in models of appropriate prehistoric plants). It’d be up-to-date scientifically, of course, but there’d be healthy speculation to flesh out the organisms and make them believable. The goal would be to portray prehistoric organisms not much differently from how one would modern ones. It’d basically do all the things Walking with Dinosaurs did well. Ideally, it’d go over all of the history of life and give due time to more than just big and famous species/groups/localities. It’d pay attention to stuff like, say, conodonts and the marsupials of Riversleigh.

[lacusovagus]

Among pterosaurs, a partial skull broken into several pieces is not a bad fossil when each one of these is a distinct species (except the two ones in the lower right with the prominent palatal ridge):

(source)

[jurassicsunsets]

Re pteranodon ask: aren't there modern birds with beaks designed for that exact fish scoop method? I remember watching an Attenborough documentary where he said "Well, a lot of X with broken beaks" re catching their beaks on stuff. Can't recall name.

Hmm, that’s interesting. If anyone recalls this, I’d be very interested in knowing!

[thuat-squared-blog]

@thatinsanefanficauthor @palaeofail-explained: The single extant vertebrate that has evolved for the skim-feeding foraging method is the black skimmer. Note that, unlike pterosaurs, its beak is tapered very thinly toward the tip and is very robust and wide where it joins the face, where it is also anchored by quite strong muscles. No pterosaurs are known to have this particular combination of these required adaptations, and Mark Witton goes to great lengths to dispel the skim-feeding myth in his book.

[lacusovagus]

Fun fact: the description of Thalassodromeus spends more time talking about and supporting the skim-feeding hypothesis than actually describing Thalassodromeus.

[thuat-squared-blog]

Odd, but that’s something that Witton also discusses and dispels in Pterosaurs. Note that the original description was in 2002; his book was published in 2013.

[lacusovagus]

Indeed. The main point was it spent more time discussing a now-discredited lifestyle hypothesis than what the paper was theoretically supposed to be doing, i.e. actually describing the holotype of Thalassodromeus. And it’s not a particularly bad fossil. And now its name (”sea runner”) is a misnomer.

[lacusovagus]

What are your top palaeo documentaries?

Note that I take these in the context of the time and am avoiding the powerful influence of nostalgia. Though any ranking of top documentaries is bound to have some subjectivity anyways. That said:

Paleoworld for effectively starting it all

I feel obliged to say Walking with Dinosaurs. It’s got flaws, yes, but I really like the “wildlife documentary with prehistoric animals” style. In my opinion, it does the best job of portraying prehistoric animals as living animals out of all of them.

When Dinosaurs Ruled (the one narrated by Jeff Goldblum). It’s nothing special but it makes a good effort at explaining the science

Ice Age Giants

Conquest of the Skies

Cave of Forgotten Dreams if it counts

Dinosaur Britain, mostly due to a feathered basal theropod

Honorable mention: Dinosaur Revolution. It’s not a documentary per se but it is a fun show to watch.

[lacusovagus]

What is your favorite species of Sauropod?

I’m fond of Diplodocoids in general; Brontosaurus excelsus if I had to choose.

[jurassicsunsets]

Re pteranodon ask: aren't there modern birds with beaks designed for that exact fish scoop method? I remember watching an Attenborough documentary where he said "Well, a lot of X with broken beaks" re catching their beaks on stuff. Can't recall name.

Hmm, that’s interesting. If anyone recalls this, I’d be very interested in knowing!

[thuat-squared-blog]

@thatinsanefanficauthor @palaeofail-explained: The single extant vertebrate that has evolved for the skim-feeding foraging method is the black skimmer. Note that, unlike pterosaurs, its beak is tapered very thinly toward the tip and is very robust and wide where it joins the face, where it is also anchored by quite strong muscles. No pterosaurs are known to have this particular combination of these required adaptations, and Mark Witton goes to great lengths to dispel the skim-feeding myth in his book.

[lacusovagus]

Fun fact: the description of Thalassodromeus spends more time talking about and supporting the skim-feeding hypothesis than actually describing Thalassodromeus.

[lacusovagus]

What is your favorite Pterosaur?

Is “all of them” an option? If not I’d say a toss-up between Zhejiangopterus, Jeholopterus, and all Tapejarids.

[lacusovagus]

So if we were to find a carnivorous dinosaur from the Ukureyskaya Formation, what would we call it? For Kulindavenator (Kulinda Hunter), press 1. For Kulindaphaganax (Kulinda Eater), press 2. For Ornithophagus (Bird Devourer), press 3. For other options, press 4. Which will you choose?

Only a tooth has been discovered thus far, and it seems better to have found something before naming it. There may be something more interesting to it than the fact that it came from the Kulinda site and ate other animals. *hangs up*

(Kulindaphaganax would mean “ruler of the eaters from Kulinda” btw, “Kulinda eater” would just be Kulindaphagus)

[lacusovagus]

I’ll take paleo questions if anyone has any.

[jurassicsunsets]

I often see Pteranodon depicted with a fish in its beak. But how realistic is that, since it had no teeth? Aren't teeth essential in holding on to slippery prey? And what do we know about pteranodon's hunting methods? Was it similar to any extant waterbirds in the way it hunted?

I can’t say I’m a pterosaur expert, but Mark Witton thinks it to have been a dip feeder, possibly even diving to catch fish. As for the teeth - I don’t know. Evidently it had some way of making it work.

[lacusovagus]

Plenty of toothless birds are able to hold fish; it probably wouldn’t have been that much of an issue in Pteranodon.

(source)

When it comes to feeding habits, pelagic fishing and potentially diving birds like gannets and albatrosses could serve as good extant analogues.