Z is for Zupaysaurus

After 26 long weeks, we are now at the final dinosaur from our dinosaurian alphabet! This week, we bring you 'Z is for Zupaysaurus', a theropod from Argentina.

Zupaysaurus lived during the Late Triassic period, about 215 million years ago in northern Argentina. The name comes from the local Quechua word 'zupay' meaning devil. It was a medium-sized bipedal theropod, between 13 and 18 m in length, and weighed about 200 kg. It is known from one definitive specimen, which includes a nearly complete skull, vertebrae, and incomplete arms and legs [1]. In the original description, it was thought to have two parallel cranial crests, like those seen in Dilophosaurus. However, more recent analysis has suggested that these "crests" were simply bones that had been pushed up during deformation of the skull [2]. 

Artists impression of Zupaysaurus by FunkMonk

Like most theropods, Zupaysaurus was a carnivore. Most analyses suggest that it was a coelophysoid dinosaur, being closely related to the Antarctic theropod Cryolophosaurus, and was the first coelophysoid to be found in South America. It was found in the Los Colorados Formation of Argentina, which is thought to have been a floodplain. This formation is home to many sauropodomorph dinosaurs, like Riojasaurus, and many other tetrapods such as therapsids, pseudosuchians, and other archosaurs. In fact, it is one of the earliest known animal fossil assemblages that was dominated by dinosaurs!

And that is it for our dinosaurian alphabet! I hope everyone has enjoyed it. I'm looking for ideas of what to do for the blog in the future, so if anyone has anything they'd like to learn about, please let me know!

References
1. Arcucci, A. B., and Coria, R. A. 2003. A new Triassic carnivorous dinosaur from Argentina. Ameghiniana 40: 217-228. 
2. Ezcurra, M. C., and Novas, F. E. 2007. Phylogenetic relationships of the Triassic theropod Zupaysaurus rougieri from NW Argentina. Historical Biology 19: 35-72.

Y is for Yulong

Last week was our last dinosaur that was actually from Alberta. Now our second last dinosaur of the dinosaurian alphabet is a newly described theropod from China: Yulong. 

Yulong was described at the beginning of this year by a group of Chinese palaeontologists as well as well-known Canadian palaeontologist Philip Currie from the University of Alberta [1]. It comes from the Luanchuan County of Henan Province. Unfortunately, the exact age of the the formation is unknown, but it is likely from the Late Cretaceous based on the other animals that are found in this formation. The name Yulong is derived from the Chinese "Yu", the abbreviated name for Henan Province, and "long" meaning dragon. Only one species of Yulong is currently known, Yulong mini in reference to the fact that the specimens are very small. 

Photograph of 3 Yulong mini skulls (a-c) in right lateral view and d in right lateral view (from Lu et al. [1]). Note the scale bar showing how small these skulls are! 

Yulong was an oviraptorid dinosaur of approximately chicken size. Most oviraptorids are larger, and can reach sizes up to 8 m in length. Although Yulong is described as being chicken sized, it was likely larger as the fossils that have been found are all juveniles. Several specimens are known, including well preserved skeletons, skulls, and even a well preserved embryo coming from a nest of 26 eggs. A thin section through a rib showed no growth lines, suggesting the animal was not yet a year old when it died. 

That's it for Yulong as it's a fairly newly described species. Tune in next week for our final dinosaur of the alphabet to learn about a neat theropod from Argentina!

References:
1. Lu, J. et al. 2013. Chicken-sized oviraptorid dinosaurs from central China and their ontogenetic implications. Naturwissenschaften 100: 165-175.  

X is for Xenoceratops

Today we introduce the final Albertan dinosaur from our Albertan dinosaurian alphabet with 'X is for Xenoceratops'. This dinosaur is the only one from Alberta that starts with 'X', and was named only last year. 

In 1958, a well-known American palaeontologist named Wann Langston Jr. discovered a partial skull of a ceratopsian in the Foremost Formation (near the town of Foremost) of southern Alberta. These remains were then returned to the Canadian Museum of Nature in Ottawa, and were left undescribed. 50 years later, some palaeontologists became aware of these bones, and wondered about the animal that they belong to. Upon further examination, they concluded that it was a new animal, and named it Xenoceratops foremostensis [1]. The name Xenoceratops means 'foreign/alien horned face', referring to the fact that it is the only known ceratopsian from the Foremost Formation. It lived during the Late Cretaceous, about 78 million years ago, making it the oldest known ceratopsian found in Canada so far. 

Reconstruction of the frill of Xenoceratops foremostensis (centre) from Ryan et al. [1]

Xenoceratops was a centrosaurine ceratopsian, a group of dinosaurs that get their name from another Albertan ceratopsian, Centrosaurus. In the above image, Xenoceratops is surrounded by other centrosaurines including Centrosaurus (B), Styracosaurus (C) and Pachyrhinosaurus (F). As you can see, it has a very different frill from the others: the midline of the frill bore two thick bony knobs,  two pointed spikes (pointing to the rear and top of the animal in life), several small bumps, and a larger bony projection in the most anterior (forward) position. 

Through analysis of the bones, they determined that Xenoceratops was the most primitive centrosaurine found thus far. Unfortunately, the fragmentary nature of the remains makes it difficult to know for sure where it would have sat in the ceratopsian family. An unprepared skull found in the same region in 2010 does have portions of the face including elongated orbital horns, and has been referred to Xenoceratops. It also may have had  low, ridge-like nasal ornamentation, like those seen in Albertaceratops and Medusaceratops. 

This find was especially exciting for palaeontologists as it was only the second dinosaur fossil found in the Foremost Formation from more than just teeth. Very few outcrops of this formation are present, making it difficult to excavate and less likely to find fossils than the younger Oldman and Dinosaur Park Formations also of southern Alberta. Unsurprisingly, the species found in this formation are from known groups of dinosaurs from this area, but they are consistently more basal in their respective groups. 

Xenoceratops is yet another ceratopsian from Alberta, and is unfortunately the last dinosaur that we will talk about from Alberta, since no 'Y' or 'Z' dinos exist from our province. Stay tuned for next week, with a theropod from China!

References
1. Ryan, M.J., et al. 2012. A new ceratopsid from the Foremost Formation (middle Campanian) of Alberta. Canadian Journal of Earth Sciences 49: 1251-1262.

W is for Wintonotitan

Unfortunately, there are no dinosaurs that start with 'W' from Alberta, so we're going to talk about a dinosaur from Australia this week. You may have noticed that I haven't talked about any sauropods (long-necked dinosaurs) at all during this series. That is because no sauropod fossils have ever been found in Alberta, so I'm going to take advantage of that and talk about a sauropod from Australia in 'W is for Wintonotitan'.

Wintonotitan fossils were first found in 1974, but were named to the genus Austrosaurus, the only Cretaceous sauropod from Australia known at that time. In 2009, the partial skeleton originally found consisting of a scapula (shoulder blade), partial left and right arms, and fragmentary vertebrae, ribs, hips and more were named as the type specimen of Wintonotitan wattsi [1]. Some caudal (tail) vertebrae found later were also referred to this species. It lived during the mid Cretaceous (approximately 100 million years ago) of Australia, found near a town in the northwest (Queensland) called Winton, hence the name. It is a basal titanosauriform, which includes well known dinosaurs like Saltasaurus and Argentinosaurus, and like other sauropods, it was a large herbivore that walked on all four legs. The fossils of Wintonotitan were found in a sandstone, along with fish fragments, a theropod tooth, and several plant fossils. It lived alongside pterosaurs, other dinosaurs like Australovenator and Diamantinasaurus, insects, bivalves, and more. It lived among many plants like ferns, ginkgoes, flowering plants, and more.

Wintonotitan by T. Tishler from Hocknull et al. [1]

And that's it for Wintonotitan! Next week, we'll talk about our final Albertan dinosaur in the alphabet, with 'X'. Also, don't forget, we are now open to the public for the season! Why not plan to visit us this weekend? The forecast looks great!

References
1. Hocknull, S.A. et al. 2009. New mid-Cretaceous (latest Albian) dinosaurs from Winton, Queensland, Australia. PLoS ONE 4: e6190. doi:10.1371/journal.pone.0006190

V is for Vagaceratops

This week on the Albertan dinosaur alphabet we have yet another ceratopsian in 'V is for Vagaceratops', the only 'V' dinosaur from Alberta. In 2001, a new species of Chasmosaurus was named, "Chasmosaurus irvinensis". It was distinguished on the basis of a broad snout, absence of orbital horns (the position instead occupied by pits and rugose bosses), a square-shaped frill, and other highly technical characters [1]. It also had 10 forward-facing 'hornlets' (epiparietals) on the back of the frill. It is known from southern Alberta, the Dinosaur Park Formation to be exact, from the Late Cretaceous (about 75 million years ago). The type specimen was a fragmented, but nearly complete skull, while two other skulls were also referred to this species. 

Vagaceratops by Nobu Tamura

As is often the case in palaeontology, further analysis years later suggested that this species was, in fact, not a Chasmosaurus. While describing two other ceratopsians (Kosmoceratops and Utahceratops) from Utah, an analysis suggested that it was more closely related to Kosmoceratops [2]. They erected the name Vagaceratops meaning 'wandering-horned-face', in reference to the fact that the group made of Kosmoceratops+Vagaceratops has been found in Alberta and Utah. While other studies have also found this relationship, not all researchers agree. 

Vagaceratops is yet another example of the many species of horned dinosaur present in Alberta during the Late Cretaceous. They showed a very wide diversity, and there are constantly more species being found. 

Next week, we will be talking about a dinosaur not from Alberta, as there are no Albertan dinosaurs that start with 'W'. And remember, Jurassic Forest will soon be opening to the public for the season! Stay tuned for more details!

References:
1. Holmes, R.B. et al. 2001. A new species of Chasmosaurus (Dinosauria: Ceratopsia) from the Dinosaur Park Formation of southern Alberta. Canadian Journal of Earth Sciences 38: 1423-1438.
2. Sampson, S. D. et al. 2010. New horned dinosaurs from Utah provide evidence for intracontinental dinosaur endemism. PLoS ONE 5: 12292. 10.1371/journal.pone.0012292

U is for Unescoceratops

Last week we talked about the theropod Troodon, and this week, we bring you 'U is for Unescoceratops', a small horned-dino relative from the Dinosaur Park Formation of Alberta. 

Unescoceratops is a leptoceratopsid that lived during the Late Cretaceous (about 76 million years ago) in southern Alberta. Currently, only one specimen is known, a partial left dentary (lower jaw). It was named in 2012 by Canadian palaeontologist Michael Ryan, and several others, including Philip Currie. It was found in Dinosaur Provincial Park, which is a Unesco World Heritage site, hence the name Unescoceratops [1]. The only species currently known is Unescoceratops koppelhusae, in honour of Eva Koppelhus for the invaluable work she has done in vertebrate palaeontology and palynology (study of fossil pollen). The bone was first found in 1995 and shelved as it was assumed to be too impartial to identify. By comparing the partial jaw to other known leptoceratopsids, they were able to determine that it was a new genus, and in fact is an advanced leptoceratopsid. 

Partial left dentary of Unescoceratops (image from Ryan et al. [1])

As you can see, this is a small portion of bone that was used to identify and name this species. This is very common in palaeontology, and palaeontologists are often stuck with small bone fragments to identify. Based on the relative size and comparison to other better-known species, Unescoceratops was between 1-2 m long, and weighed less than 90 kg. Leptoceratopsids are smaller than their better known horned relatives, the ceratopsids, which include large animals like Triceratops, Styracosaurus, and Pachyrhinosaurus. 

For an excellent artist's rendition of what Unescoceratops may have looked like, check out Julius Csotonyi's website here (Unescoceratops is the top one). 

This is the only dinosaur that starts with 'U' from Alberta, and we'll continue on with the horned dinosaurs next week with 'V'! Only a few more weeks left of the dinosaur alphabet, then we'll return to our regular weekly posts about palaeontology.

References

1. Ryan, M.J. et al. 2012. New leptoceratopsids from the Upper Cretaceous from Alberta, Canada. Cretaceous Research 35: 69-80.

T is for Troodon

Last week in our Albertan dinosaurian alphabet we talked about the hadrosaur Saurolophus, and now we're going to talk about a well known theropod in ' T is for Troodon'. 

Troodon is a genus of theropod dinosaur from the Late Cretaceous (about 75 million years ago) of North America, with fossils being found as far north as Alaska and as far south as New Mexico. The name means 'wounding-tooth' in reference to the small, pointed, serrated teeth that are characteristic of this dinosaur. As a carnivore, it may have used these serrations much in the same way that you would use a steak knife to cut through meat. However, these teeth are also similar to herbivorous dinosaurs like Stegoceras and lizards, suggesting it may have been an omnivore. In fact their teeth were so similar to pachycephalosaur teeth that for a long time, the pachycephalosaurs were known as troodontids until Canadian palaeontologist Charles Sternberg noted their differences and named the group Pachycephalosauridae in 1945 [1]. Troodon was a relatively small theropod, reaching 2.5 m in length and stood less than a metre tall. It may have weighed as much as 50 kg. It had a large sickle-shaped claw on each foot that it was able to retract and raise while running, and was likely a fast runner. The eyes of Troodon were quite large compared to other dinosaurs, which may mean it was nocturnal, and they pointed forwards, which likely gave it binocular vision and depth perception. It also had the largest brain to body size ratio of any other dinosaur, suggesting it was a more intelligent dinosaur.

Image of Troodon formosus teeth from The Childrens Museum of Indianapolis

The genus was first named from a single tooth from southern Alberta, which is problematic when trying to determine the rest of the animal, as teeth can sometimes be very similar between genera and species. Again, we can highlight the difficulty in naming species from fossils. The first non-tooth remains were named in 1932, but placed in a separate genus (Stenonychosaurus), and a more complete specimen found in 1969 was as well. However, Philip Currie united Troodon, 'Stenonychosaurus' and 'Pectinodon' under the genus Troodon, suggesting they are all the same genus [2]. Of course, as is the story with many dinosaurs, this has been questioned and reviewed since. A more recent study suggests that what we now think of as Troodon formosus is most likely not a single species, or even a single genus especially since many of these identifications are based on single teeth [3]. They also note that since the holotype is based on a single tooth, the name Troodon may be a nomen dubium, which literally means 'dubious name'. Obviously significant work is required to determine what is going on in the complicated history of Troodon. 

Egg nests of Troodon formosus have been found in Montana that have revealed many aspects about the reproduction of Troodon. They laid eggs two at a time, over the period of a day or so, and incubated the eggs by covering them with their body or with soil [4]. Eggs are found roughly in pairs, suggesting they had two functioning oviducts, and appear to have a reproductive system that is intermediate between crocodiles and birds, as we would expect. Furthermore, their eggs were also intermediate in size between crocodiles and birds. The nests were dish-shaped, 100 cm in diameter, and had 16-24 eggs. 

That's it for Troodon. You can see a feathered Troodon at Jurassic Forest, and remember that we will be opening in less than 3 weeks! Another interesting fact about Troodon: it is Phil Currie's favourite dinosaur! Next week we'll be talking about the only 'U' dinosaur from Alberta, a ceratopsian. 

Other 'T' dinosaurs from Alberta:
Tetrapodosaurus
Thescelosaurus
Torosaurus
Triceratops
Tyrannosaurus

References
1. Sternberg, C.M. 1945. Pachycephalosauridae proposed for dome-headed dinosaurs, Stegoceras lambei, n. sp., described. Journal of Paleontology 19: 534-538
2. Currie, P.J. 1987. Bird-like characteristics of the jaws and teeth of troodontid theropods (Dinosauria, Saurischia). Journal of Vertebrate Paleontology 7: 72-81.
3. Zanno, L.E. et al. 2011. A new troodontid theropod, Talos sampsoni gen. et sp. nov., from the Upper Cretaceous Western Interior Basin of North America. PLoS ONE 6: e24487. doi:10.1371/journal.pone.0024487
4. Varricchio, D.J.  et al. 1997. Nest and egg clutches of the dinosaur Troodon formosus and the evolution of avian reproductive traits. Nature 385: 247-250.