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Anzu

Named after the mythological bird-like Anzû – and also nicknamed “the chicken from hell” – Anzu wyliei was one of the larger known oviraptorosaurs, measuring about 3m long (9’10”).

Its fossils are some of the most complete for a North American member of this dinosaur group, with four different specimens representing about 80% of the whole skeleton.

Living right at the end of the Cretaceous, about 66 million years ago in North Dakota and South Dakota, USA, Anzu inhabited the ancient floodplains of Hell Creek and appears to have been a fairly fast-moving omnivorous generalist. It had a large crest on its head made of rather fragile thin-walled bone, which may have been used for display or sound amplification similar to the casque of modern cassowaries.

Some of the fossil specimens also show evidence of healed injuries, including a broken rib and an arthritic toe.

Kerberos

Named after the mythical dog Cerberus, Kerberos langebadreae was a member of an early group of carnivorous placental mammals known as hyainailourids.

These large-headed predators were part of the hyaenodont lineage, evolutionary cousins to modern carnivorans that convergently developed similar shearing carnassial teeth in their jaws. Hyainailourids originated in Africa during the late Paleocene or early Eocene, and repeatedly dispersed into Eurasia and North America before eventually going extinct in the mid-Miocene.

Kerberos was one of the earliest of its kind known from Europe, living in Southern France during the mid-Eocene about 41-38 million years ago. It was close in size to a small American black bear, standing around 65cm tall at the shoulder (2’2″), not nearly as large as some of its later relatives but still making it one of the biggest carnivorous mammals in Europe at the time.

It was a heavily-built animal with a fully plantigrade posture, and would have been an active apex predator hunting similarly-sized early ungulates. While it wasn’t anatomically specialized for fast running it didn’t really need to be – it’s important to remember that modern bears have a similar chunky flat-footed build and yet can move surprisingly quickly.

Its incredibly powerful jaw muscles and premolar teeth adapted for bone-cracking also suggest it ate like a hyena, efficiently consuming entire carcasses.

Tanystropheus hydroides

Tanystropheus is one of the classic Triassic weirdos, a bizarre archosauromorph easily recognizable with its ridiculously long neck.

Mainly known from mid-Triassic deposits on the Swiss-Italian border, dating around 247–235 million years ago, fossils of the species Tanystropheus longobardicus have been found in two different “morphs” – small forms less than 2m long (6’6″), and larger ones up to 6m long (19’8″).

For a long time the smaller fossils were thought to be juveniles, but while they certainly had juvenile-looking facial proportions they also had very different teeth compared to the larger forms. They had pointed teeth at the front of their mouths and multi-cusped cheek teeth further back, and the “adults” had jaws containing only the pointed teeth, suggesting very different diets and lifestyles between the two size classes.

Extreme changes in dentition and diet during maturation aren’t unheard of in fossil species, but something particularly odd was going on here. Larger forms over 2m long always had just the pointed teeth, and there were no signs of intermediate tooth arrangements at all.

And a new study using x-ray microtomography has given an answer: they weren’t actually the same species!

Turns out the smaller Tanystropheus longobardicus were all skeletally mature adults, already fully grown at that size. The larger ones were a completely separate species occupying a different ecological niche to their smaller relatives, and have been named Tanystropheus hydroides in reference to the mythical hydra.

Comparison of the skulls of *T. hydroides* and *T. longobardicus*

[ From fig 3 in Spiekman, S. N. *et al* (2020). Aquatic Habits and Niche Partitioning in the Extraordinarily Long-Necked Triassic Reptile *Tanystropheus*. *Current Biology*. https://doi.org/10.1016/j.cub.2020.07.025 ]

While the exact lifestyle of Tanystropheus is an ongoing paleontological argument, Tanystropheus hydroides at least appears to have been much more on the aquatic side of things, with nostrils positioned on the top of its snout and its pointed teeth forming a “fish trap” in its jaws.

Stomach contents suggest it mainly ate fast-moving aquatic prey like fish and cephalopods, but its body wasn’t really adapted for strong swimming and so it couldn’t have been catching them via active pursuit. Instead it was probably an ambush predator hunting in a similar manner to some plesiosaurs, using its incredibly long neck and relatively small head to carefully approach prey species without the rest of its body startling them, and then catching them with fast snapping sideways lunges.

Eons Roundup 8

Once again it’s a PBS Eons commission roundup day!

An illustration of an extinct baleen whale. It's looks very similar to modern rorquals, with pleated throat grooves. — Cerro Ballena rorqual

An illustration of an extinct seal. it has an unusually long neck. — Cerro Ballena rorqual

An unnamed Cerro Ballena rorqual whale and the long-necked seal Acrophoca, from “How the Andes Mountains Might Have Killed a Bunch of Whales”
https://www.youtube.com/watch?v=iNk6r5WljGc

An illustration of an extinct pseudosuchian, a relative of modern crocodiles. It resembles a dinosaur much more than a croc, standing bipedally, with a long neck, tiny arms, and a long counter-balancing tail. — Shuvosaurus inexpectatus

A skeletal diagram of an extinct pseudosuchian, a relative of modern crocodiles. It resembles a dinosaur much more than a croc, standing bipedally, with a long neck, tiny arms, and a long counter-balancing tail. — Shuvosaurus inexpectatus

The poposauroid pseudosuchians Shuvosaurus (life restoration) and Effigia (skeletal) from “When Dinosaur Look-Alikes Ruled the Earth”
https://www.youtube.com/watch?v=QsmV34Co32c

Spectember Epilogue

Now that Spectember has wrapped up, and I’m catching my breath before we return to the regular paleo-theming of this blog, a couple extra notes:

Anyone who suggested a concept during the original submission period back in May, but didn’t see it get used this month – don’t worry! I got far more entries than I could possibly fit into the schedule (almost a hundred), and they were all wonderfully creative ideas, so I’m going to try to do something with them at a later date.

(Everyone else, please be aware I’m not currently accepting extra specevo suggestions. While I appreciate all the enthusiasm I can’t take on even more work right now.)

Also, here’s a few other neat specevo things that I didn’t have time to go into detail about this month:

Spectember #22: Land Dolphins 2 – The Beakening

And so we finish Spectember as we started… with ridiculous land dolphins!

Transcript for the text on the image under the cut:

Spectember #21: Moon Camels

Transcript for the text on the image under the cut:

Spectember #20: Sapient “Dinosauroids”

Transcript for the text on the image under the cut:

Spectember Interlude: Furahan Biology

Created by Gert van Dijk, a Dutch professor of neurophysiology and a talented artist (often writing under the name Sigmund Nastrazzurro), the Furaha project has been in development since 1979 – starting as a series of paintings of speculative alien creatures, and eventually expanding to detailed essays on their anatomy and ecology.

Set on the planet Nu Phoenicis IV, Furaha documents the natural history of the world and its plants and animals using paintings, illustrations, CG models, and even animations to show how their limb arrangements work. Although only a small number of organisms are featured on the main site, the associated blog provides much more information, including the incredible amount of scientific background that goes into the creation of the Furahan ecosystems.

Few specevo projects are this rigorous, with van Dijk using physical and biological constraints along with computer simulations to figure out the biomechanics of how Furahan creatures live and move, from the giant millipede-like rusps to the four-winged flying tetrapterates to the swimming membranes of the cloakfish. One of the most heavily debated subjects over the years has involved trying to determine if floating balloon-like “ballont” animals are actually possible.

The blog also occasionally discusses other elements of speculative biology and creature design, including reviews of other spec projects and media.

A fully illustrated book version of Furaha is currently in the works – although being a solo project entirely in van Dijk’s spare time it’s very much a “it’ll be done when it’s done” situation.

Spectember Interlude: Bird Is The Word

Serina is a huge and ambitious speculative worldbuilding project by Dylan Bajda, better known as Sheatherius or Sheather888.

Set on a fictional habitable exomoon, roughly Mars-sized but with enough density to give it about 75% the gravity of Earth, the world of Serina was initially terraformed with a very specific goal in mind. Many species of microorganisms, algae, plants, fungi, and invertebrates set up and stabilized the starting conditions in a mostly-tropical climate, along with a few small live-bearing poeciliid fish in aquatic ecosystems. But on land just one vertebrate species was ever introduced – the domestic canary bird, Serinus canaria domestica.

And, like a massive-scale version of how impoverished island ecosystems often evolve in strange directions in isolation, the initial colonists of this world went to diversify and flourish over the next 300 million years. Ants briefly dominate the early ecosystems and then go on to develop complex symbiotic relationships with bamboo plants, sunflowers become trees, guppies begin to adapt to terrestrial lifestyles, and derived canaries fill a wide range of ecological niches in the air, land, and seas, with some forms even experimenting with mouth-brooding eggs or live-bearing their young.

As time goes on the inhabitants of Serina become increasingly weird and alien compared to their ancestors, shaped by changing climates and devastating mass extinctions. Examples include tentacle-faced birds, highly successful and diverse mammal-like terrestrial tripodal fish, giant manta-ray-like sea snails, and a particularly bizarre lineage of birds with metamorphosing life stages.

With detailed descriptions and numerous lavish illustrations in Sheather’s characteristic art style (all done entirely with a mouse in MS paint and GIMP!), Serina has been in development since early 2015 and is currently still ongoing, with the timeline now in its finale and approaching the end of the moon’s habitable period.

Sheather has also created several other spec projects, including the deliberately fantastical setting of Sheatheria, its successor/reboot Pluvimundus, and the monkey-world Atelemundus (created as a commission for grazatt).

Tomorrow: alien biomechanics!