Author Archive

Know Your Bones: August 2015

he_who_is_nobody
he_who_is_nobody
Mon Aug 03, 2015 7:55 pm by he_who_is_nobody

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

he_who_is_nobody
he_who_is_nobody
Mon Jul 06, 2015 8:27 pm by he_who_is_nobody

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

he_who_is_nobody
he_who_is_nobody
Sun Jun 07, 2015 2:56 pm by he_who_is_nobody

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.

Know Your Bones: May 2015

he_who_is_nobody
he_who_is_nobody
Mon May 04, 2015 12:30 pm by he_who_is_nobody

Last month’s challenge only lasted a day, because tuxbox was able to guess the correct answer with ease.

 

Dire Wolf

 

This critter is indeed a dire wolf (Canis dirus).

 

 photo 2015-01-09114449_zps2f1b6a2d.jpg

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

 

Dire wolves lived throughout North America and parts of South America during the Pleistocene 240,000 to 10,000 years ago, most likely evolving in North America. Dire wolves would have been one of the top predators during this time and may have prayed upon a few previous challenges. Dire wolves were most likely pack hunters like their modern wolf counterparts. It was also once thought that they were bone crushers, because of their large and robust size, but lack specialized teeth for such a task.

 

 photo 2013-10-04114325_zpsedf9305f.jpg

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

 

The average size for dire wolves is ~1.5 meters in length and a weight of 79 kilograms. This makes it roughly the same size as a modern gray wolf (Canis lupus), but far more robust. It would have had more muscles, including larger jaw muscles, and larger canine teeth than modern gray wolves. Dire wolves also had larger skulls, but shorter legs than gray wolves. The more muscular build and larger bones on the dire wolves would have helped it take down the larger prey animals alive during the Pleistocene. However, once those large prey animals started to die out, the smaller gray wolf would have been able to outcompete the dire wolf for the smaller game left in North and South America.

 

Moving on to this month’s challenge:

 

 photo 2013-03-03092212_zps42400bc5.jpg

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

 

Good luck to all that participate.

Know Your Bones: April 2015

he_who_is_nobody
he_who_is_nobody
Mon Apr 06, 2015 12:36 pm by he_who_is_nobody

Last month’s challenge appeared to be no challenge to League of Reason’s resident rockhound Isotelus. She gave the correct answer within a day of the blog going up.

 

Edmontosaurus annectens. They’re like the cockroaches of Alberta’s fossil megafauna. Dig a hole and you’re probably going to find at least a piece of one. :P

 

This critter is indeed Edmontosaurus annectens and it is indeed an extremely common fossil.

 

 photo 2015-02-06 11.39.14_zpsd3bsgwtu.jpg

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

 

Edmontosaurus lived during the Cretaceous 73 to 65.5 million years ago. They ranged widely across western North America, seemingly living along the Western Interior Seaway. Edmontosaurus belong to the hadrosaurid clade, which are popularly called duck-billed dinosaurs. Edmontosaurus belongs to a crestless group of hadrosaurid, unlike a previous “Know Your Bones” challenge. The specimen used in last months blog is actually famous for having what appears to be a bite mark on its tail from a Tyrannosaurus.

 

Edmontosaurus reached a length of ~13 meters (the skull alone was ~1 meter long) and could weigh up to 4 tons, making them one of the largest hadrosaurids to have ever lived. As a means of locomotion, Edmontosaurus were likely able to walk on all fours or on just their hind limbs. Edmontosaurus is also famous for having several skin impressions, which allows us to know what most of the skin of this animal looked like in life. Edmontosaurus had teeth that grew in columns of six teeth, and had around 50 columns in each jaw. The teeth were continually replaced throughout the animal’s life. However, the beak of an Edmontosaurus was toothless and was extended by a keratinous material, much like modern birds.

 

Moving on to next month’s challenge:

 

 photo 2015-01-09133458_zps29f325f9.jpg

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

 

Good luck, as always.

Know Your Bones: March 2015

he_who_is_nobody
he_who_is_nobody
Tue Mar 03, 2015 11:57 am by he_who_is_nobody

Last month’s challenge was extremely easy. Thus, I did not just want the name of the critter, but why it was such an important critter as well. With in a matter of hours Inferno named the critter, and about a day later edited his post to say why it was so important.

 

Archaeopteryx lithographica

EDIT: Why is it important? Because Darwin predicted it. There was no link between birds and dinosaurs, then Archaeopteryx showed up. In Darwin’s lifetime.

 

This critter is indeed Archaeopteryx lithographica and Inferno is correct that it fulfilled a prediction Darwin made within a few years of the prediction being made.

 

 photo 2014-01-10111452_zps436afe7e.jpg

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

 

Archaeopteryx lived during the late Jurassic, 150 to 145 million years ago in southern Germany. During that time, Europe was located close to the equator and was a large archipelago of islands in a shallow ocean. Archaeopteryx was not a very large animal, reaching 50 centimeters in length. Even though Archaeopteryx is popularly known as the first bird, it has a lot more in common with other theropods (especially the dromaeosaurs). Some of those features are a mouth full of teeth, three un-fused finger bones that included claws on each, a long bony tail, and feathers. One of the features that Archaeopteryx possesses that aligns it with birds is the atypical flight feathers found on its arms and legs. The feathers suggest that Archaeopteryx could at least glide if not outright fly. Scans of the skull of Archaeopteryx shows that it had a larger brain, including a larger vision center, than most other dinosaurs at the time, which also suggest gliding/flight capabilities.

 

The fossil used in last month’s challenge is known as the Berlin Specimen, and it is the most famous specimen of Archaeopteryx (and one of the most famous fossils in the world). However, the reason it is the most famous specimen is because it is the most complete, not because it was the first specimen found. The first skeletal remains of Archaeopteryx were found in 1861 and are known as the London Specimen. The London Specimen is missing a head, so the skull anatomy of Archaeopteryx was not known until the discovery of the Berlin Specimen in 1880, and its discovery further fulfilled Darwin’s prediction.

 

Moving on to this month’s challenge:

 

 photo IMAG0176_zpsd11161e7.jpg

(Taken at the Denver Museum of Natural History and Science)

 

Good luck and have fun.

Know Your Bones: February 2015

he_who_is_nobody
he_who_is_nobody
Tue Feb 03, 2015 5:57 pm by he_who_is_nobody

Last month’s challenge was extremely hard. Once again, the bone fragments cause the most problems for the participants. However, Isotelus came  the closest with:

 

At least in the photo it doesn’t look to be very old relatively speaking, so I’m going to guess it’s an Ice Age-ish horn core and partial skull of an ancient bovid, possibly Bison of some sort. Size is hard to assess definitively, but I’m guessing it’s not a modern Bison or B. latifrons. B. priscus or antiquus?

 

Isotelus was correct in that this is an Ice Age critter; it was indeed a horn core and partial skull of a Bison. Still, she did not think it was a Bison latifrons when this partial skull is indeed from B. latifrons. Nevertheless, I believe that if I used a scale in that photo, she would have come up with the correct answer.

 


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

B. latifrons lived throughout North America 500,000 to 20,000 years ago during the Pleistocene. B. latifrons is the largest species of Bison (and possibly bovid) known. An adult male was ~2.5 meters at the shoulder and weighed over 2,000 kilograms. From tip to tip (including the outer sheath that grew over the bone core), B. latifrons had horns that measured ~2.4 meters across.

 

B. latifrons inhabited mostly woodlands and open forests, which means it was most likely a browser, feeding off shrubs and trees, unlike modern Bison. B. latifrons most likely used its large horns defending itself from predators and fighting for territory and mates. B. latifrons is not only possibly the largest bovid, but also one of the largest artiodactyls to have ever lived (on land).

 

Moving on to thiqs month’s challenge:

 

 photo 2014-01-03095825_zpsccbfb783.jpg
(Taken at the New Mexico Museum of Natural History and Science)

This one should be an easy one, so easy in fact that I would like to know the name of the critter and why it is so important.

Know Your Bones: January 2015

he_who_is_nobody
he_who_is_nobody
Sun Jan 04, 2015 6:43 pm by he_who_is_nobody

Last month’s challenge appeared to give everyone a hard time since it went a whole two days before someone took a guess. However, after a few days of silence, Isotelus once again correctly named this critter.

 

Rhamphorhynchus muensteri

 

This critter is indeed Rhamphorhynchus muensteri.

 

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

R. muensteri lived during the late Jurassic 156 to 145.5 million years ago. Its fossils are found in Germany, with several possible specimens of Rhamphorhynchus found in England, Spain, and Tanzania. R. muensteri reached a size of ~1.26 meters from snout to tail with a wingspan of ~1.81 meters. However, the smallest known specimen is a (hatchling) ~290 millimeters in length, but would have still been capable of flight. R. muensteri was a long-tailed genus of pterosaur, and was less specialized than the contemporary short-tailed pterosaurs.

 

R. muensteri had needle-like teeth that were forward facing, the tip of its beak was sharp and curved up, and lacking teeth. When the jaws were closed, the teeth fit together like a closed zipper. This suggests that R. muensteri had a diet mostly made up of fish and other marine animals. Adult R. muensteri had a diamond-shaped vane at the end of their tail, which possibly was used to signal for mates; the diamond-shaped vane does not appear on smaller specimens assumed to be juveniles, and their beaks are not as sharp and curved.

 

Moving on to next week’s challenge:

 

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

 

Good luck to everyone who is playing and I promise that this one will be the last difficult one for a while.