Tag Archives: fossils

Know Your Bones: March 2016

Last month’s challenge went unguessed, meaning the final bragging rights for Know Your Bones belongs to me.

 

So, what is the name of the critter in last month’s challenge? It is Coelophysis bauri.

 

 photo Dayatthemuseum082_zps3be8952d.jpg
(Taken at the New Mexico Museum of Natural History and Science)

 

Coelophysis bauri lived during the late Triassic 208 to 228 million years ago. Most specimens are found in New Mexico, however, several specimens of related species (specimens that would be classified as Coelophysis) have been found worldwide, dating to as late as the early Jurassic. Coelophysis is one of the earliest dinosaurs known to science and the earliest known from complete specimens. Coelophysis was ~3 meters in length and would have stood ~1 meter at the hip. Coelophysis is a theropod with sharp curved teeth. It possessed four fingers on its forelimbs, which is the basal trait for theropods. It is believed that Coelophysis was a fast and agile predator.

 

 photo 2013-03-03091919_zpsaa913bc8.jpg
(Taken at the New Mexico Museum of Natural History and Science)

 

Coelophysis is one of the earliest dinosaurs discovered, being named by Edward Drinker Cope in 1889. Coelophysis means “hollow form,” because Cope noticed that it possessed hollow bones, something shared with all later theropods. Coelophysis also possessed a furcula (i.e. a wishbone) and a sclerodic ring seen in the orbit of the skull. The sclerodic ring allowed for muscle attachments which would have given Coelophysis amazing vision, much like modern birds of prey. As pointed out above, Coelophysis is one of the earliest dinosaurs and it already had all these traits that are found in modern birds. It would not be surprising to find out that Coelophysis also possessed feathers.

 

 photo 2013-07-26113514_zpsc84222fd.jpg
(Taken at the New Mexico Museum of Natural History and Science)

 

Thank you for everyone that ever participated in this. I did enjoy it, but I feel my time is better spent blogging about a different subject.

Know Your Bones: February 2016

Last month’s challenge must not have been as challenging as I thought. The correct answer was given by WarK within an hour of the blog going up.

 

Deinonychus antirrhopus

 

This critter is indeed Deinonychus antirrhopus.

 

 photo 2015-12-11 12.19.12_zpssnatmoko.jpg
(Taken at the New Mexico Museum of Natural History and Science)

 

Deinonychus lived during the early Cretaceous 115 to 108 million years ago. Deinonychus stood ~87 cm at the hip, reached ~3.4 meters in length, and weight ~73 kilograms. Deinonychus lived in what is now the modern western U.S. with possible fossils of it found in eastern states. Deinonychus belongs to the dromaeosaurid clade. Deinonychus (meaning terrible claw) is named for the claw found on the second toe of each foot. This claw was retractable, meaning that it kept it off the ground so it would remain sharp for the animal’s entire life. It also had three sharp claws found on each hand.

 

Bite marks from Deinonychus have been found on herbivorous dinosaurs. Measuring the amount of force needed to puncture the bone reveals that Deinonychus had a bite strength roughly the same as an American alligator. It is believed that Deinonychus lived and hunted in packs. Working together, they would have been able to take down much larger animals. The first Deinonychus specimen discovered is what reignited the idea that birds were closely related to dinosaurs in the 1960s. Since than, it is now believed (based on specimens of closely related animals) that Deinonychus also possessed feathers; in fact, the whole dromaeosaurid clade could have possessed feathers.

 

Moving on to next month’s challenge:

 

 photo 2013-10-04112707_zpse725be22.jpg
(Taken at the New Mexico Museum of Natural History and Science)

 

Above is the last Know Your Bones challenge I will be doing for a while. I am going to focus this blog in a different direction. I just wanted to finish off with this specimen, because it is one of my favorites.

Know Your Bones: January 2016

Well, last month no one took a guess at the challenge. I am chocking that up to the up-tick in activity the blog has had recently and the holidays. Because of that and the fact that I am feeling very lazy, I am just going to repost the same challenge for this month.

 

 photo 2013-12-27110604_zps44be6f46.jpg
(Taken at the New Mexico Museum of Natural History and Science)

 

Good luck again to everyone that plays and have a happy 2016 everyone!

Know Your Bones: December 2015

Last month’s challenge brought out a few good guesses and two that were correct. However, like so many other times, only one person was the most correct. Last month that happened to be our resident paleontologist Isotelus with the more correct answer.

 

A phytosaur; I know there’s some reassigning going on, so Pseudopalatus/Machaeroprosopus? I don’t know species names, at least not for this genus.

 

This critter is indeed Machaeroprosopus buceros formally known as Pseudopalatus buceros. Red identified the wrong species name and I was unaware when I picked the critter that its genus had changed. Thus, Isotelus should get extra kudos. Honestly, I picked this obscure critter mainly so WarK would not get a third victory in a row.

 

 photo 2015-11-13 10.17.46_zpssyixbclr.jpg

(Taken at the New Mexico Museum of Natural History and Science)

 

M. buceros lived during the late Triassic 205 million years ago and is found only in New Mexico. However, Machaeroprosopus species are found through out the southwest of the U.S. M. buceros grew to 3-4 meters as adults. M. buceros was an aquatic predator that would have lived its life much like a modern crocodilian, which is catching fish or ambushing prey at the shoreline. During the late Triassic, a giant swamp covered most of what is now the modern southwest of the U.S. Several different species of aquatic predator are found throughout this area and time range.

 

 photo 2014-01-10095114_zps1f2ad95b.jpg

(Taken at the New Mexico Museum of Natural History and Science)

 

Even though it looked very similar to modern crocodilians, M. buceros was a phytosaur, which are only distantly related to crocodiles, making this a classic case of convergent evolution. One of the easiest ways to tell the difference between a crocodilian and a phytosaur is where the nasal aperture is located. On a phytosaur, the nasal aperture is located on the back of the head near the eyes, while a crocodilian’s nasal aperture is located on the tip of their snouts. The specimens of M. buceros show sexual dimorphism in the skulls. There is a robust morph believed to be male and a gracile morph believed to be female. This is mainly based on our observations of crocodilians and their sexual dimorphism in which the males are the larger of the two.

 

Moving on to next month’s challenge:

 

 photo 2013-12-27110604_zps44be6f46.jpg

(Taken at the New Mexico Museum of Natural History and Science)

 

Good luck to everyone that plays.

Know Your Bones: November 2015

I have to say, I am surprised it took so long for anyone to take a stab at guessing this iconic fossil. By the trepidation of our winner and the following guesser, perhaps the readership of this blog finds me to be a trickster. With that said what critter once owned the skull from last month’s challenge?

 

Something tells me this is too easy to be correct.

 

Nope WarK, I was not trying to trick anyone. This critter is indeed the tyrant king of the dinosaurs, Tyrannosaurus rex.

 

 photo IMAG0555_zpsa92a2380.jpg
(Taken at the New Mexico Museum of Natural History and Science)

T. rex lived during the late Cretaceous 68 to 65 million years ago; it also happened to be one of the last non-avian dinosaurs that we know about. It ranged across western North America, with its fossils (mostly teeth) found from Alaska down to Mexico. T. rex could grow as large as ~4 meters at the hip, 43 meters long and weigh between 5.5 to 6.8 tons. This makes T. rex one of the largest predatory dinosaurs and one of the largest predators to ever walk the earth. Full-grown animals had a skull ~1.5 meters in length. The teeth of T. rex ranged from 30 cm long (including the root) to 13 cm long (including the root) in adults. The teeth would have been continuously replaced during life and were re-curved with ridges on the surface. T. rex famously has small arms (about the length of an adult human’s arm) with only two fingers. However, the arms appear very muscular, leading paleontologists to speculate that the arm could have been used for something (e.g. assisting in lifting the animal up when it sat down) instead of just a vestigial structure.

 

 photo 2013-10-04111227_zps27b761c7.jpg
(Taken at the New Mexico Museum of Natural History and Science)

 

Over 30 specimens of T. rex have been discovered to date, making T. rex a very well studied dinosaur. T. rex is a theropod, but within that clade, it is closer in relation to dromaeosaurs than it is to other giant carnivores, such as Allosaurus. Because of this, and fossil finds of earlier relatives, it is possible that T. rex could have had feathers. However, a few skin impressions has only shown scales, which leads some to speculate that  T. rex could have had full body feathering as a hatchling, but later sparse to no feathering as an adult due to its large size.

 

 photo 2015-10-30 09.59.06_zpsabkivlad.jpg
(Taken at the New Mexico Museum of Natural History and Science)

 

Two possible footprints have been found of T. rex, one of which was found in New Mexico. It measures 83 cm by 71 cm and possesses a “heel” print plus the print of the dewclaw-like forth digit found on the feet of T. rex. T. rex is also famous for being the first dinosaur found with soft tissue associated with it. In 2005, Dr. Mary Schweitzer published her discovery of it, since than several more finds have been made of soft tissue. Dr. Schweitzer and others have found trace soft tissues, and when they are analyzed and compared to living organisms, it shows that T. rex’s closest living relatives are birds. These findings align with the conclusions paleontologists were making for decades based on morphology.

 

Moving on to next month’s challenge:

 

 photo Dayatthemuseum015_zps0c57051f.jpg
(Taken at the New Mexico Museum of Natural History and Science)

 

Good luck to all that play.

Know Your Bones: October 2015

There were only two guesses for last month’s challenge, both correct, but one being more correct. I have a feeling that the reason only two people guessed is because this one was such an easy specimen. So, who won, who was the more correct of the two?

 

Camarasaurus

 

It turned out to be WarK, because the other guesser gave the wrong species name. The critter from last month is Camarasaurus supremus.

 

 photo 2014-01-10111738_zps5a90e232.jpg
(Taken at the New Mexico Museum of Natural History and Science)

 

Camarasaurus lived during the late Jurassic 155 to 145 million years ago. It ranged across most of North America and is an extremely common dinosaur in the Morrison Formation. Camarasaurus had an average length of 18 meters and weighed up to 18 tons. Remarkably, several complete skeletons of Camarasaurus have been discovered in Wyoming, Colorado, Utah, and New Mexico. Based on their fossil abundance it is assumed that they roamed around North America in large numbers during the late Jurassic and may have had one of the largest populations of sauropods, if not dinosaurs, known thus far.

 

Camarasaurus means “chambered lizard;” it most likely got this name from the hollow bones that make up much of the vertebra or the many fenestrae found on the skull. Camarasaurus had chisels shaped teeth that were 19 cm long. The shape of the teeth and strength of the skull suggest that Camarasaurus specialized in eating coarser plant matter. This is different from other sauropods, thus Camarasaurus most likely inhabited a different environment then its cousins that also lived during this time. Camarasaurus remains are found together in a lot of sites, suggesting that they lived and died in herds.

 

Moving on to this month’s challenge:

 

 photo 2013-10-18105402_zps59c3c2eb.jpg
(Taken at the New Mexico Museum of Natural History and Science)

 

Here we have a terrifying critter, which is appropriate for this month. Thanks for playing and good luck.

Know Your Bones: September 2015

Last month’s challenge led to some great guesses early on. However, the win goes to two of the later commenters. Last month, I was not looking for a specific species, but the name of the group, which makes our first winner Dragan Glas.

 

Ammonites

 

The critters are indeed ammonites (Ammonoidea). However, a minute before Dragan Glas’s guess, red also made a correct guess:

 

Perhaps otherwise – Coilopocerus nova mexicanus

 

The specimen labeled number 3 is a Coilopoceras springeri. The species is incorrect, but being able to nail down a specimen to a genus level from just a single photo is amazing. Specimen number 1 is Romanicera mexicanum and specimen number 2 is Spathites puercoensis.

 

 photo 2015-07-24 13.42.37_zpszpxyqnxe.jpg
(Taken at the New Mexico Museum of Natural History and Science)

 

Ammonites lived from the middle Devonian until the end of the Cretaceous giving them a temporal range of 400 to 66 million years ago. Ammonites are a common fossil in Paleozoic and Mesozoic marine deposits across the world. These critters would have made up a huge amount of the biodiversity of any sea during the Paleozoic and Mesozoic. Most species of ammonites have the spiral shape seen by the three species from last month’s challenge, a few others had spirals that resemble the modern nautilus, others had straight cone shaped shells, and still others had fancy shaped shells (heteromorphs). However, some of the spiral shape shelled ammonites could grow some fancy spikes to ornate their shells as well.

 

Ammonites make great index fossils, because they speciated quickly and distinctly. Thus, identifying a species (or group of species) of ammonite can actually pin down the date of a location. Ammonites can range in size from as small as 23 cm to ~2 meters in diameter. Although ammonite shells are very common, the soft bits of their body are not and very little is known about it. However, ammonites are believed to be carnivorous (like most swimming cephalopods), had a beak, and perhaps ten arms. Ammonites survived a few mass extinction events, including the end Permian extinction (the Great Dying), but finally went extinct during the K-Pg event that also took the non-avian dinosaurs.

 

Moving on to next month’s challenge:

 

 photo 2013-11-12150430_zps94e1d4e0.jpg
(Taken at the Dinosaur Museum and Natural Science Laboratory)

 

Thanks to everyone that is playing and I am hoping to read some more great guesses this month.

Know Your Bones: August 2015

Last month’s challenge sparked a great discussion about the fenestrae found on the skull of some dinosaurs. By the end of it, we had come up with two or three different projects for Isotelus to work on. The discussion was so involved that only one person guessed on the actual challenge.

 

PS The dinosaur in this month’s challenge is Allosaurus. As you said, it was easy! :D

 

Dragan Glas is correct; this critter is Allosaurus.

 

 photo 2014-01-10111750_zps802d443e.jpg
(Taken at the New Mexico Museum of Natural History and Science)

 

Allosaurus fragilis lived during the late Jurassic from 155 to 145 million years ago. The average length of an Allosaurus was 8.5 meters (however, some fragmentary remains have been interpreted as being ~12 meters) and weighed in at ~2.3 tons. Allosaurus possessed a large skull ~84 cm in length, which was lightly built, with ~20 pairs of teeth on both the top and bottom jaw. The teeth of Allosaurus were constantly being replaced throughout the life of the animal, making their teeth very common fossils. The skull also had a pair of small horns above the eye. The purpose of the horns is unknown, but could be related to display, combat against other Allosaurus, or just keeping the sun out of the eye of the animal. Allosaurus possessed short (for its size) forearms that had three fingers, which had strong, large curved claws. The forearms were very powerful and most likely used for hunting.

 

Allosaurus was one of the largest predators of the Jurassic and would have prayed upon a number of different dinosaurs. Allosaurus is one of the best-understood theropods (perhaps dinosaurs) we have ever discovered. In the Cleveland-Lloyd Dinosaur Quarry (Utah, USA) alone there are at least 46 different individuals of Allosaurus discovered. This quarry has individuals ranging from multiple age groups, from specimens that are less than a meter in length on through full-grown adults. This has allowed paleontologists to reconstruct a wonderful life history for Allosaurus.

 

Moving on to this month’s challenge:

 

 photo 2015-07-24 13.40.46_zpsoy9kf1zp.jpg
(Taken at the New Mexico Museum of Natural History and Science)

 

I am not looking for a specific species name this week (but major props to anyone that can do that), but what are these specimens examples of? Good luck to everyone that participates.

Know Your Bones: July 2015

I chose last month’s challenge believing it would be a tricky one. However, I was truly impressed by the answers given, although none of them were correct, but the knowledge of prehistoric critters the readers of this blog possesses impresses me. I truly thought everyone would simply guess Triceratops and move on. As I said, this is not Triceratops, nor any of the ceratopsians given in the comments. Thus, this once again makes me the winner of this month’s challenge for stumping everyone.

 

However, the critter that owned the skull in last month’s challenge was Pentaceratops sternbergii and I will give you five guesses as to what its name means.

 

 photo Dayatthemuseum001_zps5d38b135.jpg
(Taken at the New Mexico Museum of Natural History and Science)

 

Pentaceratops lived during the Cretaceous 75 to 73 million years ago. It is mostly found in New Mexico and Colorado (U.S.). It would have reached a length of ~8 meters and weighed ~5,500 kg. Pentaceratops had five horns, two large horns over the eyes, one small horn over the nose, and two small horns, which protrude sideways out of under the eyes. Pentaceratops also possessed a large frill with two large fenestrae in it. The fenestrae found on the frill were most likely away for cutting down the weight of the skull. Pentaceratops specimens include some of the largest skulls of all terrestrial animals. The frill and horns were most likely used for display, with the possibility of blood being pumped into the frill to change its color slightly. The frill and horns were also probably used in defense as well as jousting between each other.

 

Pentaceratops belongs to the ceratopsian clade. That clade also belongs to the ornithischian clade, meaning that Pentaceratops and the other ceratopsians are more closely related to hadrosaurids and thyreophorans than they are to saurischians. Pentaceratops is believed to be an herbivore and thought to have traveled in large herds similar to modern bovines. Another striking feature Pentaceratops possesses is its sharp beak, which was most likely used for ripping open large and tough vegetation or digging into the ground for tubers.

 

Moving on to next month’s challenge:

 

 photo IMAG0167_zps074c8041.jpg
(Taken at the Denver Museum of Nature and Science)

 

Here is an easy one, since last month’s challenge ended up being so difficult. I am looking for the critter on the left, since the critter on the right was already featured. Good luck to all that participate.

Know Your Bones: June 2015

Last month’s challenge was a stumper. For most of the month, only one person dared to give a guess. Nevertheless, it was not until days before the month ended that Isotelus came in with the correct answer.

 

The Dicynodont Placerias hesternus

 

This critter is indeed Placerias hesternus.

 

 photo 2015-06-05 09.36.01_zps3si6xnjp.jpg

(Taken at the New Mexico Museum of Natural History and Science)

 

Placerias lived during the late Triassic 221 to 210 million years ago. Placerias would have reached a length of ~3.5 meters and weighed in at nearly 1000 kilograms, making it one of the largest herbivores known about during this time. It was also one of the most common animals around during the late Triassic. Placerias had a beak and two tusks, which are common traits for dicynodonts. Both males and females had the same size tusks, thus they would have most likely used them in obtaining food and defense; not necessarily in finding mates. It is thought that Placerias would have had a life style similar to modern hippopotamuses, wallowing in semi-shallow rivers and lakes and spending little time outside of water.

 

 photo 2015-06-05 09.36.59_zps7guvthxk.jpg

(Taken at the New Mexico Museum of Natural History and Science)

 

Even though Placerias lived during the “Age of Dinosaurs” (the Mesozoic), it was not a dinosaur, it is a synapsid. Along with being a synapsid, it is also a therapsid, meaning it is very closely related to modern mammals, but falls outside of the modern mammal clade. Fossil animals, such as Placerias, are found across the world and were key evidence to help establish that at one time in earth’s past, all the continents were of one land mass (Pangaea). Dicynodonts are the second most successful synapsid clade and are only surpassed by mammals in their diversity and longevity.

 

Moving on to next month’s challenge:

 

 photo Dayatthemuseum036_zpsb8b3d5b6.jpg

(Taken at the New Mexico Museum of Natural History and Science)

 

Since last month’s was so difficult, I am hoping this one is much easier.