Academy of Natural Sciences: Tiny Titans

The Academy of Natural Sciences recently had a seasonal exhibit showcasing dinosaur babies and eggs, called "Tiny Titans".  I was fortunate enough to be able to walk through it a few times and take photographs.

I was pleasantly surprised to see that this exhibit has a lot of full skeletal mounts of dinosaurs, often posed with young or on nests.  The first one you meet when you come in is of the small ceratopsian, Protoceratops flanked by several youngsters.  Protoceratops was almost always depicted as guarding a nest of eggs in popular media and art.  Ironically, the eggs that we thought belonged to it actually came from a different dinosaur, Oviraptor.  Since then, however, we have found actual Protoceratops eggs and babies as well.

Protoceratops skeletal mount with babies.

Speaking of nests and Oviraptor, what kind of eggs and babies exhibit would this be without oviraptorosaurs?  The exhibit sports a beautiful life-sized cast of a fossil nest from what was a some king of oviraptorosaur, judging by the shape of the eggs (long, narrow) and their placement.  We know this kind of dinosaur laid eggs in pairs, and in a ring pattern so the parent could safely sit in the middle and cover them with its arms.

Nest of giant oviraptorosaur eggs.  My hand for scale.

There is also a great skeletal mount of Conchoraptor, in a brooding position.  It was exciting to see an oviraptorid that wasn't Citipati showcasing this for a change.

Concoraptor on a nest of eggs.

One thing that really excited me was the sculpture of the dinosaur embryo that was on the cover of National Geographic Magazine in 1996.  This was based on a dinosaur embryo that was nicknamed "Baby Louie".  We now know this embryo was a kind of oviraptorosaur, recently named Beibeilong.

Baby Louie!  If this model was made now he'd have a beak, since we know he was an oviraptorosaur.

There was a case showcasing a dinosaur egg (from as sauropod judging by how perfectly round it was) that had turned into a geode.  Silica had gotten inside the egg through the porous shell during the fossilization process and formed beautiful crystals on the inside.  I had no idea that could happen to a dinosaur egg.  It was neat to see.

That dinosaur egg geode was incredible.

Another really cool feature about this exhibit was a station where the visitor could look at fossilized embryonic titanosaur skin under a powerful magnifier.  I love a good sample of fossil dinosaur skin.  They are so rare ans so precious, especially for paleoartists!

Close up view of embryonic dinosaur skin.

This exhibit also featured several skeletons of the small ceratopsian, Psittacosaurus, which is known from many individuals on the fossil record, including babies.  There was a cast on the wall of what appeared to be an adult Psittacosaurus that had its body wrapped around thirty four baby Psittacosaurus.  All the skulls of the babies were above their bodies, which shows that they died very fast and they fossilized in their life poses.  Unfortunately it was found out in 2013 that the adult's skull was never a part of this fossil, and was glued on to make it more dramatic.  Also it was found out that the skull of the adult was from an individual that was too young to have had babies of its own when it died, so it couldn't have been the parent anyway.  That being said, this fossil is still proof that baby Psittacosaurus were at least gregarious in life, which is an exciting all on its own.

Dramatic fossil of thirty four baby Psittacosaurus that died together quickly in was could have been a burrow collapse.  The adult skull was not found with them.

The last part of the exhibit has a stretch of life-sized images of famous dinosaurs, including Diplodocus, Maiasaura, Triceratops, Stegosaurus, and Tyrannosaurus, by paleoartist, Luis Rey.  In front of each of these dinosaur images was a small fence-like pen, with a roughly three to four foot model of  that dinosaur's "baby".  I could see they were going for a dinosaur petting zoo kind of vibe.  This part had potential to be really cool, since we actually do know a lot about the babies of those particular dinosaurs.  It would have been a great opportunity to show the proportional differences between babies and adults and how they would have changed as they aged.  Unfortunately that is not what was offered.  These "babies" were more or less poorly done, shrunken versions of the adults.

The Luis Rey art is beautiful.  If only the models would match.

The Triceratops looked like it was kind of trying, since its horns were shorter, but it still didn't match what we know baby Triceratops looked like.  The Maiasaura looked more like a hypsilophodontid than anything else.  The "baby" Tyrannosaurus was the most offensive.  I think it was modeled after the Tyrannosaurus toy from the company, CollectA, which isn't even an accurate representation of an adult Tyrannosaurus, let alone a baby, which we know would have looked very different, with longer legs and an overall lighter build.  The kids in the exhibit seemed to be loving it, however, and it was a great opportunity for selfies...it was just a missed opportunity to educate without taking anything away from the fun.

The adult T.rex is wondering why her baby is so ugly.

Overall this was a cool exhibit.  It was a neat contrast to see so many tiny baby skeletons and eggs after looking up at the massive adult skeletons in the museum's main fossil hall.  There was also a lot of interactive and truly educational content for any age of visitor.  Unfortunately, Tiny Titans is no longer at the Academy of Natural Sciences, but it could pop up at another museum soon!

References

Pu, Hanyong, et al. “Perinate and Eggs of a Giant Caenagnathid Dinosaur from the Late Cretaceous of Central China.” Nature Communications, vol. 8, 2017, p. 14952., doi:10.1038/ncomms14952.

Zhao, Q. (2013). "Juvenile-only clusters and behaviour of the Early Cretaceous dinosaur Psittacosaurus". Acta Palaeontologica Polonica.

Bajadasaurus: Beast of the Week

This week we will be looking at a newly discovered dinosaur that looks right at home in a Tim Burton movie.  Enter Bajadasaurus pronuspinax!

Bajadasaurus was a plant-eating dinosaur that lived in what is now Argentina during the early Cretaceous period, about 140 million years ago.  From snout to tail it would have measured roughly thirty feet long, but this is based on only the few bones of this dinosaur that were actually found.  The genus name translates to "Bahada reptile" in reference to the region in Argentina where its bones were found.  The species name, pronuspinax, translates to "forward-leaning spine" in reference to the spines that grew from its neck.

Life reconstruction of Bajadasaurus in watercolors by Christopher DiPiazza.

Bajadasaurus was a member of the sauropod order of dinosaurs, the well-recognized dinosaurs with small heads, long necks, large bodies, and long tails.  Within that group, Bajadasaurus was a member of the dicraeosaurid family.  Dicraeosaurids were sauropods that flourished mostly in the late Jurassic to early Cretaceous and were relatively small compared to other sauropods.  (if you consider thirty feet small) Dicraeosaurids also tended to have, relatively speaking, shorter necks when compared to those of other sauropods.  Their most diagnostic characteristic is elongated neural arches of some kind. (A neural arch is the top part of a vertebra.  If you run your finger down the back of your neck or your own spine you can feel them in the form of little bumps.)

Skeletal mount of Bajadasurus' skull and neck on display in Buenos Aires.

Elongated neural arches are not rare in the dinosaur world.  Meat eaters, like Spinosaurus and Acrocanthosaurus had them.  The dicraeosaurid sauropod, Amargasaurus, had long, backward-pointing ones on its neck.  Bajadasaurus, however, had extended neural arches unlike any other dinosaur that we know of so far.  Similar to Amargasaurus, it had long, spike-like extensions growing from its neck bones, but they curved forwards, towards the front of the animal, instead of its tail.  The exact evolutionary reason for this is a mystery.  Some suggest this was defense against predators, presenting a wall of pointy things whenever the dinosaur bent its head down to eat low-growing plants or to drink.  Some say they were for display within the species.

Known bones from Bajadasaurus.  Note the single vertebra with the two spines.  Also note the majority of the skull, including teeth.  Image from the most recent paper, published in 2019.

All this being said, it is important to keep in mind that only one neck vertebra of Bajadasaurus has been found so far, sporting two of these long spikes.  Looking at close relatives, like Amargasaurus, the most logical thing to do is assume it had similar structures on the rest of its neck, but as of now we can't know for sure, let alone the exact lengths and shapes of these other spikes, if there were any.  On the flip side, we do have a lot of Bajadasaurus' skull, including its teeth and eye sockets, which is pretty awesome considering sauropod skulls are notoriously the most rarely found parts.  The eye sockets were relatively large and almost perfectly circular, suggesting this dinosaur had decent vision.  The teeth, like those of most sauropods, were concentrated to the front of the mouth, and were shaped like skinny little pegs, ideal for raking vegetation into the mouth to be swallowed.

References

 PA Gallina, S. Apesteguía, JI Canale and A. Haluza, A new long-spined dinosaur from Patagonia sheds light on sauropod defense system , in Scientific Reports , vol. 9, 2019, p. 1392

Prehistoric Beast at the Academy of Natural Sciences: Part 2

Last time I gave you a taste of the Academy of Natural Sciences' main fossil hall.  If you missed it, check it out here.  Today, we will take a look behind the scenes at some of the fossils that most visitors to the museum don't get to see.

Remember, most natural history museums aren't just for the entertainment of the public, they are also working research facilities, so the exhibits you see on display are usually just a tiny fraction of what that museum actually has to offer.  A big reason why so many specimens are kept away from the public is because, especially in the case of fossils, they are safer that way.  Being in a dark, cool, drawer is a lot less taxing then mounted out in the open air under bright lights all day.  There is also protection against the off chance that a visitor might break the rules and try to touch, climb on, or even steal the specimen. (Which happens more often than you might think.)  Because of this many of the skeletons on display are cast replicas, with the real specimens locked away safely elsewhere. 

The second reason why so many specimens are kept behind the scenes is that it's much easier for scientists to work with them, like taking measurements or scanning, that way.  If a fossil is on display, mounted up, or in a glass case, it is a hassle to get it safely out and into a lab for study, then put it back safely after.

As stated in my last article at the Academy, since it is so incredibly old for a museum, some of the specimens kept here have a very deep and rich history.  The Academy of Natural Sciences actually has a valuable collection of ice age mammal fossils. (unfortunately there aren't many mammal fossils actually on display to the public.)  The first of which was shown to me was a Mastodon tooth that originally belonged to former United States president and founding father, Thomas Jefferson.

Mastodon teeth that once were part of Thomas Jefferson's collection.  Note how worn down the one on the left, being held by Jason Poole, is.

One of these teeth was worn down and was actually concave by the time the animal died.  This tells us the Mastodon it belonged to was old when it died.  Jefferson was fascinated by Mastodon, and was hoping there might still be some alive in the still unexplored by Europeans, Western part of the United States.

Jason Poole showing us the Academy's MASSIVE Bison latifrons skull.  Look at the size of that horn core!  Not imagine if it wasn't broken and had a layer of keratin over it!

Elsewhere in the fossil drawers were America's first two scientifically described non-avian dinosaurs.  The museum has casts of both of them on display for guests to enjoy, but it also has the original real specimens!  New Jersey's official state fossil, Hadrosaurus foulkii and New Jersey's resident tyrannosauroid, Dryptosaurus aquiluguis.  In addition to the classic dinosaurs all kids know, like Tyrannosaurus and Triceratops, Dryptosaurus and Hadrosaurus have always been two of my absolute favorite dinosaurs since I was little.  Knowing they existed near where I grew up made me proud to be from New Jersey, and seeing them for real and in person (their bones at least.) was a dream come true.

The real bones of Hadrosauris foulkii.  This was the start of American dinosaur paleontology back in the 1800s.

That's my starstruck face posing next to the real fossils of my favorite meat-eating dinosaur, Dryptosaurus.

Another view of Dryptosaurus' bones.  Jason Poole is holding up the dinosaur's famous giant hooked hand claw. 

The Academy is also home to some more recently discovered dinosaur fossils.  Scientists in association with this museum were responsible for discovering and describing the Jurassic sauropod dinosaur, Suuwassea in the early 2000s.  Some of the original bones of this fascinating beast are on display, but most of the material is safely locked down below.

Original vertebra from the sauropod dinosaur, Suuwassea, being held up by Jason Poole.

Special thank you to Jason Poole who took us down into the depths of the museum's collection to show us all these invaluable fossils.

Our trip through the Academy of Natural Sciences isn't over yet!  Join me next time for a tour through one of the museum's seasonal exhibits about dinosaurs that isn't open anymore!

Eretmorhipis: Beast of the Week

This week we will be looking at an unusual reptile that swam in the oceans during the Triassic.  Let's check out Eretmorhipis corroldongi!

Eretmorhipis lived in what is now China, during the early Triassic Period, about 250 million years ago.  It measured a little over two feet long from snout to tail and was probably a predator of small marine animals.  The genus name translates to "oar fan" in reference to its wide, flat flippers.  Eretmorhipis was a member of the hupehsuchian order of reptiles, which flourished during the early Triassic and were related to the more well known ichthyosaurs.

Watercolor life reconstruction of Eretmorhipis by Christopher DiPiazza.

Eretmorhipis had a long, tube-like body that was reinforced with thick overlapping ribs and extensive gastralia (belly ribs).  Its front limbs were modified into proportionally huge, wide flippers.  Its back limbs were also flippers but were a little smaller in comparison.  These paddle-like limbs no doubt helped Eretmorhipis propel itself through the water with the help of its tail, which would have also been powerful in life.  Eretmorhipis also had ten bony plates, called osteoderms, in a line down its back.  These may have helped it protect itself from predators, or perhaps were used in some sort of combat within the species.  They also may have helped regulate body temperature, by acting like solar panels to absorb more heat from the sun. Modern reptiles, like crocodilians and turtles, have been known to use their bony armor for all these purposes.

Photo of the latest uncovered specimen of Eretmorhipis, which preserved the skull, showcasing the unusual bill-like snout.

Eretmorhipis' head was proportionally tiny compared to the rest of its body.  Furthermore, it had proportionally tiny eyes compared to the rest of the head!  It also had a long flattened bill-like mouth that squared off at the tip, very similar to that of modern platypus.  Platypus also have tiny eyes, and therefore poor eyesight.  Even though the platypus is not closely related to Eretmorhipis, it may give us clues to help determine how the prehistoric reptile may have hunted.  If it was similar to the platypus, it may have relied on other senses, instead of sight, and sifted around in the mud and sand underwater with its bill to look for small aquatic prey, possibly invertebrates, to snap up and eat.

References

Xiao-hong Chen; Ryosuke Motani; Long Cheng; Da-yong Jiang; Olivier Rieppel (May 27, 2015). "A New Specimen of Carroll's Mystery Hupehsuchian from the Lower Triassic of China". PLoS ONE. 10 (5): e0126024. 

Long Cheng, Ryosuke Motani, Da-yong Jiang, Chun-bo Yan, Andrea Tintori, Olivier Rieppel. Early Triassic marine reptile representing the oldest record of unusually small eyes in reptiles indicating non-visual prey detection. Scientific Reports, 2019

Pachyrhinosaurus: Prehistoric Beast of the Week

This week belongs to a unique ceratopsian dinosaur, Pachyrhinosaurus!  Pachrhinosaurus was a very successful plant-eater that lived in what is now Canada and Alaska during the Late Cretaceous period.  There are actually three different species within this genus that range in age from 73 million to about 69 million years old.  Pachyrhinosaurus was one of the largest ceratopsians, the biggest individuals measuring over twenty feet long from beak to tail.  The name, Pachyrhinosaurus, translates to "Thick Nose Dinosaur".

Pachyrhinosaurus perotorum life reconstruction in watercolor by Christopher DiPiazza.

While many other ceratopsians had horns growing from their noses and brows, Pachyrhinosaurus had a wide, flat structure called a boss, earning it its genus name.  In addition to this boss, Pachyrhinosaurus of all species had horns growing out of their frills.  Some curved outwards, while others curved more dramatically downwards.  There is even a decent amount of variation among horn shape and length among adults of the same species.  This could be due to age or even sex.  Further more, according to the baby Pachyrhinosaurus skulls on the fossil record, we know they didn't have any of this dramatic headgear until much later in life, so it may have been a sexual display adaptation, or possibly for fighting fellow adults for dominance.

Pachyrhinosaurus lakustai skull on display at the Royal Belgian Institute of Natural Sciences.

As stated above, Pachyrhinosaurus is known from three different species.  The two Canadian species are called Pachyrhinosaurus canadensis and Pachyrhinosaurus lakustai.  P. lakustai is the oldest, having lived between 74 and 73 million years ago.  P. lakustai was unique in that many specimens had prominent horns growing out of the centers of their frills.  Some refer to it as the "unicorn dinosaur" because of this.  Pachyrhinosaurus canadensis is slightly younger, having lived between 72 and 71 million years ago, with a bigger nose boss.  Finally, there is the youngest species that lived all the way up in what is now Alaska, Pachyrhinosaurus perotorum, which lived between 79 and 69 million years ago, with the overall most extensive nose boss of the three species.  (There is certainly individual variation between specimens of each species. Not every individual P. perotorum had a bigger nose boss than every single P. canadensis, for instance.)

Three species of Pachyrhinosaurus are currently recognized.

Pachyrhinosaurus is a well-studied dinosaur, known from many specimens.  In fact, there were over a dozen skeletons of this dinosaur all discovered together in the same area in Alberta, Canada, called Pipestone Creek.  It is possible that the poor dinosaurs died trying to swim across a river that had flooded.  Among these specimens there were small juveniles all the way up to large adult animals.  This tells us that Pachyrhinosaurus was a dinosaur that at least sometimes lived in groups and most likely looked out for its young.

Pachyrhinosaurus canadensis at the Geological Society in Copenhagen.

When alive, Pachyrhinosaurus would have co-existed with many other dinosaurs including Edmontosaurus regalis and the tyrannosaurid, Albertosaurus.  The Alaskan Pachyrhinosaurus perotorum would have probably met Nanuqsaurus, another tyrannosaurid.

Pachyrhinosaurus belongs to a group, or subfamily, called centrosaurinae within the ceratopsian group.  Centrosaurine ceratopsids tended to have taller, thicker snouts, longer tails, and shorter frills than other large ceratopsids.  They also typically (not always) were devoid of long brow horns and instead sported large, bony structures on their snouts.  Other examples of centrosaurine ceratopsians are Styracosaurus and Sinoceratops.

That's all for this week!   Join us next week for the last prehistoric animal review of 2013!  As always feel free to comment below or on our facebook page! 

References

Anthony R. Fiorillo and Ronald S. Tykoski (2012). "A new species of the centrosaurine ceratopsid Pachyrhinosaurus from the North Slope (Prince Creek Formation: Maastrichtian) of Alaska". Acta Palaeontologica Polonica 57 (3): 561–573. doi:10.4202/app.2011.0033.

C. M. Sternberg. 1947. New dinosaur from southern Alberta, representing a new family of the Ceratopsia. Geological Society America Bulletin 58:1230

Currie, P.J., Langston, W., and Tanke, D.H. (2008). "A new species of Pachyrhinosaurus (Dinosauria, Ceratopsidae) from the Upper Cretaceous of Alberta, Canada." pp. 1-108. In: Currie, P.J., Langston, W., and Tanke, D.H. 2008. A New Horned Dinosaur from an Upper Cretaceous Bone Bed in Alberta. NRC Research Press, Ottawa, Ontario, Canada. 144 pp. ISBN 978-0-660-19819-4

E. B. Koppelhus. 2008. Palynology of the Wapiti Formation in the northwestern part of Alberta with special emphasis on a new Pachyrhinosaur bonebed. International Dinosaur Symposium in Fukui 2008: Recent Progress of the Study on Asian Dinosaurs and Paleoenvironments. Fukui Prefectural Dinosaur Museum, Fukui 65-66.

Prehistoric Beast at the Academy of Natural Sciences

I visited Philadelphia's historical natural history museum, The Academy of Natural Sciences, my first weekend after moving to this city, almost three years ago.  I also landed a job working in their education department, and regularly volunteer prepping fossils in their lab.  That being said...for some reason I never wrote a proper post about it.  Let's fix that now.

Outside of the museum.  (Photo by Ashli Lenox)

The Academy of Natural Sciences is the oldest science research institution and museum in the United States.  This is the museum where Edward Drinker Cope worked out of during the infamous Bone Wars in the late 1800s.  It's also the resting place of the first two dinosaurs to be formally described in America, Hadrosaurus and Dryptosaurus.  Needless to say, it's a special place and should be one of the top museums to visit for anyone who likes paleontology or American history.

This awesome life-sized statue of two running Deinonychus, sculpted by Kend Ullberg, was erected in front of the museum in the 1980s.  At the time this was an extremely up-to-date depiction, especially since the idea of light, fast-moving dinosaurs was still novel.  (photo by Ashli Lenox)

When you first walk in the front doors, you are greeted by the skeleton of the giant marine reptile, Elasmosaurus, swimming at you from the ceiling.  This creature has more significance than just looking cool, however.  It was this Elasmosaurus that in some ways started the Bone Wars, the historical event when Othniel Marsh embarrassed fellow paleontologist, Edward Drinker Cope, by pointing out during Cope's debut of this skeleton, that the skull was put on the tip of the tail, instead of the neck.

In the back of the front lobby is a cast and 3D life reconstruction of Tiktaalik, a fossil that helped prove the evolutionary connection between fish and land vertebrates.  The actual fossil of Tiktaalik is currently in Northern Canada, where it was discovered, but it was brought to the Academy of Natural Sciences to be studied and published.

Tiktaalik cast and life reconstruction. (photo by Ashli Lenox)

When you first enter the Academy's fossil hall, you are attacked by a lunging Tyrannoaurus skeleton.  This is a cast of the same T. rex skeleton on display at The American Museum of Natural History, in New York, affectionately referred to by its ID number, 5027.

The T. rex is the central attraction in the Acdemy's fossil hall.  The scapula (shoulder blades where the arms attach) are erected too close together.

Right next to Tyrannosaurus, is a medley of other meat-eating dinosaur skulls, including Acrocanthosaurus, Majungasaurus, Dilophosaurus, Velociraptor, Herrerasaurus, and Eoraptor.  Lots of people come into the museum asking to see a Velociraptor, then get really disappointed when they are shown the actual skull and see how small their favorite Jurassic Park monster really was.  Luckily for those folks, we have a lovely mount of the larger dromaeosaurid, Deinonychus, in all its predatory glory, attacking a family of Tenontosaurus.

Meat-eating dinosaur skulls that are not T. rex!

While we're on the subject of Jurassic Park, the Academy of Natural Sciences showcases almost all of the main dinosaurs featured in the beloved franchise.  This is actually really cool from an educational standpoint because educators giving tours can show visitors the dinosaurs they are already somewhat familiar with and therefore, more effectively implement the real science behind them.  Not sure if having all these specific dinosaurs was on purpose, but it's convenient.

Deinonychus attacking a family of Tenontosaurus.

Another notable skeleton on display is that of the crested hadrosaurid, Corythosaurus.  It's a massive specimen, towering over almost everything else in the room, flanked by the ceratopsian, Chasmosaurus, with two Pteranodon skeletons suspended near its head.  What I really like about this display, is that the Corythosaurus mount is almost all the original fossil bones, not casts.  The only exception is the skull, which is a lightweight cast since the real one was too heavy to be safely mounted up that high.

Corythosaurus

The main fossil hall has a fair share of marine fossils.  Most impressive, in my opinion is a beautifully preserved Ichthyosaurus that spent over one hundred years at the Academy, mostly in the behind the scenes collections.  Only very recently, in 2016, it was realized, upon closer examination, that this specimen was a previously unnamed species.  It was given the full name Ichthyosaurus somersetensis, and is now on full display in the main fossil hall.

Ichthyosaurus somersetensis

The Academy of Natural Sciences has a fossil prep lab, where paleontologists and  volunteers work on cleaning off and assembling pieces of dinosaur bones collected every summer in Montana.  Most of the fossils that are currently being worked on are from the Late Jurassic Morrison Formation.  The sauropod dinosaur, Suuwassia, was discovered, prepped, studied, and scientifically described by folks from the Academy of Natural Sciences.  A glass case with a few bones from this amazing dinosaur is on display right next to the lab.  Visitors can walk right in, look at the specimens currently being prepped, and talk to /ask questions of the scientists and volunteers as they work.

Neck vertebrae of Suuwassia on display in the Academy's fossil lab.  There are more bones from this dinosaur in the museum's collections, and even more in the lab that have yet to be prepped.  We are learning more about this relatively newly discovered dinosaur every day.

Finally, I'd like to share what I am most impressed by at this museum, the first and second American dinosaurs ever described by science! (and they're both from my home state, New Jersey!) Hadrosaurus and Dryptosaurus are both on display at the Academy.  Casts of Dryptosaurus' bones are in a glass case in the main fossil hall, across from a wall mount of casts of the known skeleton of New Jersey's official state fossil, Hadrosaurus foulkii.  On the second floor, however, there is a full skeletal mount of Hadrosaurus on display.  The unknown bones of this skeleton are filled in with the bones of more completely known hadrosaurid dinosaurs, like Maiasaura.  Not only does the Academy have these two important dinosaurs on display, it is also the housing place of their real bones down below in its collections drawers.

Casts of  some of the bones of Dryptosaurus on display in the fossil hall.

Known skeletal elements of Hadrosaurus are mounted in the museum's fossil hall.

On the second floor there is a full skeleton of Hadrosaurus, supplemented with bones from other related dinosaurs to fill in the gaps.  Because of this, the right femur (from a Maiasaura) is longer than the left one (from Hadrosaurus)

There are lots of fossils on display that I did not include in this post.  In addition, there are many other exhibits, other than the fossil hall, that are worth seeing at the Academy.  If you are ever in the Philadelphia area, make sure to go see for yourself!  Stay tuned for part two of my tour of the Academy of Natural Sciences, where we will take a look behind the scenes and see fossils that you don't get to see on a regular visit!

Macrocollum: Prehistoric Beast of the Week

This week we will be checking out a newly discovered dinosaur that is currently the oldest known member of its family. Check out Macrocollum itaquii!

Macrocollum was a plant-eating dinosaur that lived in what is now Brazil, during the late Triassic period, about 225.4 million years ago.  When alive, it would have measured about sixteen feet long from snout to tail.  The genus name translates from Greek to "long neck".

Macrocollum life reconstruction in watercolors by Christopher DiPiazza.

Macrocollum is an important find because it is the oldest known member of the group of dinosaurs known as the basal sauropodomorphs, or "prosaurpopods" as they have also been called.  These dinosaurs were common during the late Triassic and early Jurassic and are characterized by having long necks and tails, and proportionally small heads.  Many of them walked on their hind legs primarily, but others could also have dropped down to all fours, as well.  Plateosaurus, Massospondylus, Mussaurus, and Ingentia, are also members of this group.  There is evidence to suggest that this group of dinosaurs would later give rise to the gigantic sauropods, like Brontosaurus and Apatosaurus.

Close up photograph of a Macrocollum skull.  Note the down-turned tip of the snout and the small, leaf-shaped teeth.

The fact that Macrocollum is from as old a time as it is, combined with its anatomy, is what makes it extremely interesting, and tells us a lot about sauropodomorph evolution.  Macrocollum had a very long neck, and proportionally small head, just like later members of its family.  This tells us that, since it is so far the oldest-known member, that the sauropodomorph body type must have happened even earlier, from an ancestor that didn't have a long neck and proportionally small head.  Many paleontologists agree that the common ancestor to dinosaurs was a meat-eater.  Macrocollum's proportionally small head, small, leaf-shaped teeth, and long neck are all adaptations for eating plants, which proves that being a plant-eater must have evolved much earlier in the dinosaur family tree, too.

Multiple skeletons of Macrocollum were discovered very close to each other.  Each individual animal's remains are highlighted in a different color.  Image from Federal University of Santa Maria.

Macrocollum is also interesting in that multiple individual skeletons were discovered nearby each other.  This suggest that this dinosaur may have been social, perhaps living in groups, or sticking with family members as an adult, which is exciting to think about and rarely supported by fossil evidence.  That being said, keep in mind it is also possible that these dinosaurs may have just congregated at a riverbed in search of a resource, like water, during a time of drought, and all died at about the same time from lack of that resource.

References

Rodrigo Temp Müller; Max Cardoso Langer; Sérgio Dias-da-Silva (2018). "An exceptionally preserved association of complete dinosaur skeletons reveals the oldest long-necked sauropodomorphs". Biology Letters. 14 (11)