STL Science Center

STL Science Center

09 December 2018

Videos of Giant Sauropods

Invest a little time in learning a little bit about Sauroposeidon today with WizScience and Dinosaurs Unearthed:



08 December 2018

The Tallest Sauropod

Sauropods were enormous animals, for the most part. They certainly have a wide range of sizes, but the absolute largest sauropod ever known was discovered in southeast Oklahoma and described in 2000 by Wedel, Cifelli, and Sanders. Trace fossils, in this case footprints, from Oklahoma, Wyoming, and Texas have long been associated with the animal as well and, despite the holotype consisting of only a few cervical vertebrae, many more bonebeds and isolated fossils have been discovered in these states since 2000. Named the "lizard earthquake god" that was "perfect before the end" Sauroposeidon proteles was estimated to have possessed a neck approximately 11.25–12 m (37–39 ft) long based on the largest cervical vertebra of a sauropod known, which measured in at 1.4 m (4.6 ft) long. That is a fairly large singular bone; almost as tall as my mother actually! It also makes the neck about 2 m (7 ft) longer than the next longest sauropod neck (belonging to Giraffatitan).
CC BY-SA 3.0 Stephen O'Connor

28 November 2018

It's in the Name

It was mentioned earlier this week that Protarchaeopteryx, as a name, translates literally to "Before Archaeopteryx". This poses a small problem because Protarchaeopteryx is a Cretaceous archaeopterygian and Archaeopteryx itself is a Jurassic animal. Geologically speaking, Archaeopteryx predates Protarchaeopteryx by approximately 25MY; though it is important to note that the accepted span of existence for Archaeopteryx is 150MYA - 125.45MYA and Protarchaeopteryx shows up in the fossil record at 124.6MYA. This means that they are not, temporally, that distant from one another. This does not necessarily reflect their phylogenetic relationship to one another. Now, the reason that we brought up the names is that the implication of the name is not actually what the name means. What I mean, and what Ji and Ji meant by that in 1997, is that Protarchaeopteryx did not come before Archaeopteryx, but rather it possess characters which appear to place it in a phylogenetically primitive position in relation to Archaeopteryx. The justification for the name as assigned by Ji and Ji was that "...it [Protarchaeopteryx] is regarded as more primitive because it has a more elongated tail, more robust pelvic girdle, longer and larger hind limb, and unfused proximal metatarsals [than Archaeopteryx]." These characters, it may not require stipulating, are more derived in Archaeopteryx. To better understand the description and read the translated version of that 1997 paper, please see the reference presented below.

Reference:
Ji, Qiang, Shu’an Ji, and Translated By Will Downs. "A Chinese archaeopterygian, Protarchaeopteryx gen. nov." Geol Sci Tech 238 (1997): 38-41.

25 November 2018

Caveats of the Internet

Any time that one searches for anything discussing birds, dinosaurs, and/or evolution, one must be aware of the confusing and argumentative cyclone of websites that are out there. Looking up an animal like Protarchaeopteryx is a part of that rule and certainly not an exception. A safe place to start is something like the WizScience video below that just presents facts that we know about this dinosaur without adding conjecture or argument to what is presented.


Of course, we cannot assume that all of the videos and websites are as neutral as those put forth by a group like the team behind WizScience. That being said, there are websites that do avoid the arguments on the internet by presenting information (and being fairly regularly updated to maintain that information) without allowing comments; it really can be as scary as I am making this sound when a website discusses the dinosaur-bird transition and key fossils and allows for commenting. Pages that are safe include:
Encyclopedia Britannica
The Natural History Museum of London
Age of Dinosaurs
Dinosaur Jungle
Enchanted Learning

24 November 2018

Early Feathers

We always love a fossil that we haven't talked about or a fossil that has had a lengthy absence and we are talking about it for the first time in a really long time. This may or may not be one of those times; I feel like we have covered Protarchaeopteryx robusta before, but searches of the entries on the blog turned up nothing. That is almost 8 years worth of entries to search though, and considering that with this year as an exception of every day entries, that is a search of almost 2500 entries. Regardless, the small "Before Archaeopteryx" feathered theropod is an interesting dinosaur that was discovered in the Yixian Formation of China in rocks that belong to the Aptian age of the Early Cretaceous (approximately 124.6 MYA). There are questions about the validity of the animal; some discussion has involved its relationship to another small dinosaur, Incisivosaurus (we may visit this animal next week to follow up). However, with that relationship in question and not cemented or ignored, another relationship is still alternatively proposed for Protarchaeopteryx; that this animal represents a basal oviraptorosaurid. Despite this ancestral mystery, we do have some idea about what the animal ate (likely mostly herbivorous but sometimes supplementing this diet with meat) and what it was covered in (symmetrical, flightless feathers) and we can therefore form a few hypotheses about the way that Protarchaeopteryx lived in and interacted with its environment and other animals.

Protarchaeopteryx holotype at the Geological Museum of China
CC BY-SA 4.0

20 November 2018

Two papers

There are two important papers that everyone interested in Rubeosaurus should take a moment to read today. These papers discuss, first, some interesting remains of "Styracosaurus" ovatus in which the authors, McDonald and Horner, introduce new remains attributed to this species and then analyze the characters and describe the phylogeny of the animal. This paper contains the naming of the new genus, Rubeosaurus, based on this material and is therefore important in knowing where the dinosaur came from and what was known about it previous to its naming in a new genus in 2010. The second paper is about a subadult specimen of the genus that was discovered somewhat recently and described by McDonald in 2017. This description is actually a revisiting of a previous description of another dinosaur (Brachyceratops) and places a young animal within the genus Rubeosaurus. Additionally, this description causes the name Brachyceratops to be considered invalid, or as we more commonly say in paleontology, it is a nomen dubium (a problem name).

17 November 2018

It Refers to Brambles

One might imagine that with a name like Rubeosaurus ovatus the person naming the dinosaur may have been poking fun at someone, but the name actually means "Bramble lizard" and references the appearance of the ceratopsian frill that makes up a good portion of the known skeletal elements. Originally named by Charles W. Gilmore in 1930 as a species of Styracosaurus, Rubeosaurus was split from that genus in 2010 by McDonald and Horner following a phylogenetic analysis conducted using new material attributed to what would be renamed Rubeosaurus. The ceratopsian dinosaur has a similar frill to its close relatives Styracosaurus and Einiosaurus. These frills all possess large parietal fenestrations and are bordered by large conical processes surrounding these cranial bones and highly ornamenting the skull. A singular and immense nasal horn is also present in Rubeosaurus, just as in its close relatives.
©Lukas Panzarin CC BY 2.5
From McDonald and Horner 2011