pterodactyloids

Caulkicephalus trimicrodon, an ornithocheirid pterosaur from the Early Cretaceous (~130 mya) of the Isle of Wight, carrying around a flapling in a similar manner to modern crocodiles.

We still know very little about the life cycle and reproduction of pterosaurs. The few known fossilized eggs had leathery shells, and may have been left buried in sand or vegetation. Baby pterosaurs (“flaplings”) seem to have been superprecocial, highly developed and possibly even capable of flight very soon after hatching.

Whether any actual parental care took place is also a mystery. So this is a rather speculative idea – but still adorable.

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Nemicolopterus crypticus: A baby pterosaur, or just small?

Size: 10 inches (25 centimeters) from wingtip to wingtip.

Time Period: The Aptian stage of the Early Cretaceous Period.

Locale: The Jiufotang Formation of China.

Name: The generic name means “forest-dwelling wing,” in reference to the animal’s presumed forest habitat. The specific name means “hidden.”

Pterosaurs astonish us humans because they were strange prehistoric creatures that lived in the sky. They looked a bit like birds, but were incredibly foreign in comparison to our feathered friends. Most astonishing of all is the size of some pterosaurs. Animals like Hatzegopteryx and Aerotitan grew to sizes never seen in other flying animals. However, not all pterosaurs were as huge and macho as the azhdarchids. Some were pretty tiny.

One such “ptiny pterosaur” is Nemicolopterus, a Chinese pterodactyloid that is currently identified as the smallest pterosaur of all. However, there might not be as much truth to this as you’d think. The fossil specimen is actually smaller than any (excepting a choice few) hatchling pterosaur, but it isn’t fully grown. Darren Naish has argued that, since pterosaurs are able to be out and about from an early age, bone fusion and ossification can occur very quickly. Factoring this into our catalog of Jiufotang faunal assemblages, we can guess that Nemicolopterus may be a hatchling of the genus Sinopterus, a decently sized tapejarid from the same area. 

All that discussion aside, there are some concrete conclusions to be made about this little fellow. Nemicolopterus is toothless, and may be an intermediate between the ornithocheiroids and dsungaripteroids. Though Nemicolopterus isn’t the best representative of its relatives’ size, some of its relatives may have evolved into the aforementioned macho pterosaurs (such as Aerotitan).

We can also confidently assert that we know just about where Nemicolopterus lived. Since this pterosaur demonstrates adaptions for grasping tree branches, it may have hunted for insects and lived in the canopy of a forest. Though most pterosaurs are known from marine sediments, and would have probably caught fish in the sea and landed on nearby structures to eat and mate, it’s clear that Nemicolopterus was found in the continental interior of its area, making it one of the few pterosaurs known to live in such a habitat. Other inland pterosaurs include Quetzalcoatlus, a “Ptexan pterosaur” whose inland habitat was originally given as evidence that it was a vulture-like scavenger. Tapejaridae, the family that Sinopterus (Nemicolopterus’s presumed adult version) belongs to, also shows similar adaptions despite the fact that some were marine.

So, though Nemicolopterus may have only been a juvenile specimen of Sinopterus, it’s still interesting. It might make us reconsider our phylogenetic assignments of other small pterosaurs, and it is one of the few inland pterosaurs discovered thus far. As we have piece together the puzzle of pterosaur “ptylogeny (okay, I tried),” we find that a bit more investigation may be required to correctly determine the identity of some flying reptiles, even our forest-dwelling pal.

pteros.com
Pteros, The Encyclopedia of Pterosaurs
From Aerotitan to Zhenyuanopterus, Pteros covers all genera of the prehistoric flying reptiles known as pterosaurs.
By Nick Garland

Pteros, The Encyclopedia of Pterosaurs launches today! 

Learn more about pterosaurs, the iconic and amazing flying animals of the Mesozoic: their evolutionary relationships, environments, diverse lifestyles and intriguing morphology, with new pterosaurs added weekly.

I’m happy to have several of my illustrations included as part of this project, alongside the images, writing, coding and research of many talented individuals!

One of my entries, Scaphognathus:
http://www.pteros.com/pterosaurs/scaphognathus.html

Pterorhynchus wellnhoferi, a ’rhamphorhynchoid’ pterosaur from the Middle Jurassic of China (~164 mya). With a wingspan of around 85cm (33"), it was probably comparable in size to a modern barn owl.

It’s known from a nearly complete specimen, with preserved soft tissue such as wing membranes, hair-like pycnofibers, a prominent head crest, and a distinctive saw-toothed tail vane.

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Aerotitan sudamericanus: Air Nomads.

Size: Though it’s too fragmentary to definitely ascertain this animal’s size, its wingspan was probably at least 16.4 feet (5 meters) in width.

Time Period: The Early Maastrichtian Stage of the Late Cretaceous Period.

Locale: The Allen Formation of Argentina, a place that was also home to Willinakaqe and Austroraptor, the former of which has been covered on this blog.

Name: The generic name means ‘air titan,’ thanks to this animal’s large size and airborne lifestyle. The specific name means ‘of South America,’ because Aerotitan was found in South America.

I’ve mentioned that animals such as Quetzalcoatlus and Hatzegopteryx are macho pterosaurs. These huge creatures were very interesting and were probably also threatening. Here, I report a fairly new one, and the first confirmed azhdarchid from South America, Aerotitan.

This creature is known only from a rostrum, or the part of the head at the end of the beak. It was a toothless animal, and probably had a spearlike beak like its fellow azhdarchids. Its snout was very long and compressed transversely. The animal, like Hatzegopteryx and company, was a semi-terrestrial predator that lived much like a modern-day stork.

The real subject of this post isn’t about Aerotitan itself, it’s about it and the many other azhdarchid taxa that have been assigned. These animals all looked very similar, and are known from similar and fragmentary evidence. This makes me question just how many of these animals were distinct taxa. Here, I propose the theory that, since azhdarchids were such large flying creatures, they could fly from continent to continent and colonize the world without being very distinct taxa. Though this is a bit Paulian in a sense (and I don’t like lumping a bunch of taxa into a genus no matter how convenient it is), this large amount of taxa has always seemed a bit questionable to me. Though I could be wrong, it’s always a little bit tricky to assign taxa.

So, though Aerotitan seems like a distinct taxa, I’ve nursed my misgivings about it for a while now. The truth is, most of the azhdarchids can’t be definitely grouped outside of a single genus. Quetzalcoatlus and Hatzegopteryx, for example, aren’t distinct save for their locations on the globe. Though research might or might not prove me wrong, I can still have my opinion.

Note: I’m sorry that this post is so short. It’s hard to blog about such a poorly-known taxon.

Pterosaur Ptuesday Nemicolopterus crypticus!

Nemicolopterus was an Azdarchoid Pterodactyloid pterosaur and smallest pterosaur known, smaller than a modern day barn swallow. It hails from the Apatian (early Cretaceous) age of China’s Jifutang formation which represents a swampy, forested environment.

N. crypticus shows adaptations to an arboreal lifestyle and likely would have fed on insects.


It is known from only a single specimen and could represent a sub-adult, possibly of SinopterusThe fossil shows a high degree of bone-fusion - typically indicative of an adult, however since pterosaur flaplings were likely highly precocial their bones may have fused early in life.  If it is a sub-adult it would represent the strategy of niche partitioning  thought to be common to pterosaurs and dinosaurs, where juveniles occupy different ecological niches than adults in order to avoid competition for resources.

sources

[1] [2] [3] [4]

Talking about Thalassodromeus, this is a personal depiction I’ve made in August 2012. I would do something different now but still this is one of the few drawings that I don’t hate.

I know that it has already been uploaded on Tumblr but trust me, this is the real deal. 

Thalassodromeus was a large pterodactyloid pterosaur found in northeastern Brazil. Thalassodromeus was believed by Kellner to have fed in a similar way to modern skimmers; trailing its lower jaw in the water while it flew. However, later research on its jaw and neck anatomy suggested that for this and other larger pterosaurs it would not be feasible to skim because of the drag: the energy expenditure would be too high. Kellner assigned Thalassodromeus to the Tapejaridae. Other analyses however, showed that it was, joined with Tupuxuara in a Thalassodrominae, more closely related to the Azhdarchidae.

The Searunner, 2012.
Coloured with Tria markers and pencils. Based on knobbed hornbill.
References: Mark Witton, Jaime A. Headden, David Peters, Mike Hanson.
Link: http://smnt2000.deviantart.com/art/The-Searunner-320498352http://ktboundary-smnt2000.blogspot.it/2012/08/the-searunner-aka-thalassodromeus.html

A small flock of Pterodactylus antiquus, represented by small juveniles (left) up to big adults (right) scope out foraging options in a Jurassic marsh. The animal on the right is luring prey to the surface through paddling forefeet, a behaviour common to (at least) several modern gull species.

From artist Mark Witton’s blog post on the biology and troubled taxonomic history of the original “pterodactyl”.

Aerodactylus scolopaciceps by Steven Vidovic:

Aerodactylus scolopaciceps is a pterodactyloid pterosaur from the Solnhofen Plattenkalk of Bavaria, Germany. Aerodactylus was a Jurassic pterosaur, like Pterodactylus. It was in fact synonymous with Pterodactylus until 2014 when Vidovic and Martill erected the genus Aerodactylus for it.

(And yes, it’s named for the Pokémon.)