Sunday, January 10, 2021

Saurosuchus: Beast of the Week

This week we will be checking out an amazing giant predator that was a neighbor to (and likely hunted) the earliest dinosaurs.  Make way for Saurosuchus galilei!

Saurosuchus was a meat-eating reptile that lived during the late Triassic period, about 231 million years ago, in what is now Argentina.  From snout to tail an adult would have measured about eighteen feet long, but some estimate this beast may have been able to grow even larger.  The genus name, Saurosuchus, translates to "Lizard Crocodile".   

Saurosuchus overpoweriing the early dinosaur, Herrerasaurus.  Watercolor reconstruction by Christopher DiPiazza.

Despite its appearance, Saurosuchus was not a dinosaur.  It was more closely related to modern crocodilians than it was to dinosaurs.  Specifically, it belonged to a group of reptiles called prestosuchidae.  Prestosuchids shared common ancestors with other pseudosuchians (broad group that includes modern crocodilians) like the poposauroids (like Shuvosaurus) and the rauisuchians (like Postosuchus). Prestosuchids were generally large land predators that usually walked on all fours and had fully erect posture with regards to their limbs, rather than a more sprawling posture, like modern lizards, or semi-sprawling, like modern crocodilians.  

Saurosuchus had a large robust skull with long, curved, serrated teeth, ideal for slashing through meat.  It had pronounced ridges on the back of its skull, implying there were large muscles attached there in life, and its neck vertebrae were relatively short and robust, which would have been an adaptation for absorbing impacts and strain in life.  This implies Saurosuchus was likely using its jaws and neck for rough activities, like overpowering struggling prey and/or forcefully dismantling carcasses as it ate.  

Saurosuchus skeletal mount on display at the Mori Arts Gallery in Japan.

Saurosuchus likely walked on all fours most of the time but probably could have reared up on its hind legs or even ran and walked short distances as a biped.  It also had rows of small bony plates, called osteoderms, running down the length of most of its body.  These may have been an adaptation for protecting the animal from bites from members of its own species, like chain mail armor, if there was any kind of intraspecies combat or cannibalism.  They also could have helped camouflage the animal better by breaking up its shape, or could have simply been for display.  (or maybe a combination of more than one of those things for all we know)

Saurosuchus was the largest and most powerful known predator from its environment, and likely could have hunted every other animal it coexisted with during its time on the planet.  Its kind would eventually go extinct and make way for more derived pseudosuchians, like the rauisuchians, and then eventually later kinds of dinosaurs, however.  

References 

Alcober, O. (2000). "Redescription of the skull of Saurosuchus galilei (Archosauria: Rauisuchidae)". Journal of Vertebrate Paleontology20 (2): 302–316.

Nesbitt, S.J. (2011). "The early evolution of archosaurs: relationships and the origin of major clades" (PDF)Bulletin of the American Museum of Natural History352: 1–292. 

Reig, O. A. (1959). "Primeros datos descriptivos sobre nuevos arcosaurios del Triásico de Ischigualasto (San Juan, Argentina)"Revista de la Asociación Geológica Argentina13(4): 257–27.

Sill, W. D. (1974). "The anatomy of Saurosuchus galilei and the relationships of the rauisuchid thecodonts"Bulletin of the Museum of Comparative Zoology146: 317–362.

Trotteyn, M.J.; Desojo, J.; Alcober, O. (2011). "Nuevo material postcraneano de Saurosuchus galilei (Archosauria: Crurotarsi) del Triásico Superior del centro-oeste de Argentina"Ameghiniana48 (1): 13–27. 

Saturday, December 19, 2020

Interview with Paleontologist: David Wilcots

David Wilcots is a geologist, paleontologist and artist living in Philadelphia where he grew up.  Mr. Wilcots is a registered professional geologist in Pennsylvania and Delaware.  He earned his Bachelor’s degree in geology at Temple University in Philadelphia, and Master’s degree in geology from Fort Hays State University in western Kansas. His master’s thesis was entitled, “Functional Morphology, Phylogeny and Paleoecology of the North American Miocene Rhinoceros, Aphelops”.  

Wilcots has over 29 years experience working as an environmental geologist and has worked for several environmental/engineering consulting companies in the Philadelphia region.  Currently David is the senior geologist for Sci-Tek Consultants, Inc., an engineering and environmental consulting company in center city Philadelphia.  

Mr. Wilcots is also a volunteer paleontologist at the Academy of Natural Sciences museum in Philadelphia in its Dinosaur preparation lab. For nine days each summer David is an expedition paleontologist in Wyoming for the Burke Museum of Natural History and Culture of Seattle, Washington.

David has also been an expedition paleontologist for the: 

 • Utah Geological Survey, Salt Lake City, Utah 

• The University of Utah Museum, Salt Lake City, Utah, and the 

• American Museum of Natural History, New York, NY.

He has given presentations about fossils at schools and has presented at S.T.E.M. programs for young people.  In 2012 David was featured on the Discovery Channel Global Education Partnership DVD entitled “Life in the Age of the Dinosaurs”.  In December of 2014 David launched the website for Dinosaurs Fossils and Adventures; DinosaursFA.com which is an on-line paleontology website for ages 8 to 18. In February 2020 he was a S.T.E.M. presenter for the Franklin Institute’s Color of Science Symposium.

Question 1: What was your earliest sign of interest in paleontology that you can remember?


DW: When I was four my parents took me to the American Museum of Natural History in New York City.  I saw the dinosaurs there and was just transfixed.  It was out of this world for me. I've been excited about dinosaurs and fossils ever since.  


Question 2: Did you have anyone who served as a role model when you were younger?  Do you still have any now?


DW: I did not have anyone that served as a role model for paleontology or geology.  I had role models in my parents when it came to how to learn and talk to people and overall how to be professional.  They were both very supportive of my interests- my brother too.  I did not grow up wanting to be like a certain paleontologist who was out there, though.  In my teenage years I didn't know any geologists or paleontologists except for Louis Leakey in in National Geographic Specials.


Question 3: You are a geologist full time.  Tell us more about your work and what its all about. 


DW: I am an environmental geologist.  I work for an engineering/environmental consulting firm. (Sci-Tek Consultants, Inc.)  In my capacity at this firm I manage environmental projects, which includes environmental site assessments, soil and groundwater sampling, borehole drilling supervision, and sometimes air and rock sampling.  I sample these media for environmental quality to test for potential contamination and to report on site contidions.


Question 4: How much of your work in geology and paleontology overlap?

DW: My job as an environmental geologist does not overlap with paleontology.  However, when I'm doing paleontology, I need my knowledge and experience as an geologist to do it effectively.  Geology allows me to read the rocks and strata that I see.  


Question 5: Was there anything you did or learned as you were on your way to your current career that you feel got you to where you are?  What sort of field experience, a class, networking with the right people, or possibly something different?


DW: My interest in geology probably kicked in during my teenage years.  Going on field trips and stopping along the highway to look at rocks fueled my fire and inspiration for geology going.  I also made a point to go to a lot of museums and as I learned more, my interests in both geology and paleontology grew.  I also watched a lot of science-based TV, like National Geographic, NOVA, Wild Wild World Animals, Marlin Perkins' Wild Kingdom, Jacques Cousteau, and several other shows kept me inspired.  


Question 6: Are the fields of paleontology and geology different now than from when you started as far as you can tell?  What would your advice be to anyone trying to make a career in paleontology (or science in general)


DW: As for geology, ground-penetrating radar technology has improved. Paleontology, however, has some newer technology, like 3-dimensional printing that has really changed the field.  You can shrink giant specimens down or expand tiny specimens up.  You can also make copies of specimens.  Twenty or thirty years ago, making copies of specimens was a long and arduous process.  3D printing has made is much easier to study fossils as well as communicate and work with a team.  You can simply send a file to someone on the other side of the world and they can reproduce it.  


Question 7: What was or is your favorite project so far? (geology or paleontology)


DW: For paleontology it would be when I was working summers in southwestern Wyoming with John Alexander with the AMNH and later the Burke Museum in Seattle.  He was looking for middle Eocene age fossils. The rocks there are about 47 million years old and the faunal variety was incredible.  We found fossil primates, early carnivores that preceded dogs and cats, rodents, birds, turtles, crocodiles, rhinos, tapirs, and large herbivores like titanitheres.  This was a very interesting time in earth's history because there were archaic animals living side by side with the ancestors of the animals we have now.  There were ecosystems dominated by browsing herbivores which isn't the case now since most modern mammalian ecosystems now are dominated by grazing herbivores.  There was a myriad of condylarths, hoofed mammals whose connection to modern mammals is still unknown.  That part of North America (Wyoming) was also home to at least three kinds of primates.  The biggest one was about the size of a house cat, the medium-sized one was about the size of a squirrel, and the smallest was the size of a mouse.  The environment had to be rich enough and have a forest canopy expansive enough to support primates, which is totally unlike anything in the United States today.  


For geology my favorite experience was hiking the Grand Canyon top to bottom to top in one day.  That was just stunning. 


Question 8: Do you have a favorite destination when it comes to fossils?  Why?


DW: Southwestern Wyoming for reasons stated above.


Question 9: You work out of Philadelphia, a major city.  Most people imagine open wild places when they think of fossils and geological formations.  What do you think people should know about the deep time history behind Philly?


DW: The bedrock in Philadelphia is hard metamorphic rock thats around 500 million years old, and devoid of fossils.  On top of that bedrock is two kinds of sediments. One is about 3 million years old and the other is only about 17 thousand years old.  These may be devoid of fossils also.  So there is a huge span of time missing from Philadelphia's observable geologic history. 


Question 10: A popular image of paleontologists is that they are constantly out in the field digging up fossils, which is true sometimes.  What people don’t realize is that a lot of paleontology work is conducted in a lab as well.  In your experience how much time have you spend in the lab and in the field?  What do you prefer?


DW: I prefer fieldwork.  I like discovering new things and being the first to see them.  I have done lab work, like cleaning and reassembling specimens.  I've also cataloged and organized specimens.  That's all fun, but I ultimately prefer being out finding and excavating fossils.  The fever for discovery is real.  


Question 11: You also run a website aimed to educate young people about paleontology.  Can you tell us more about that?


DW: I started the website to make paleontology more accessible to young people.  Some videos are on there as well as many photos that show viewers different aspects of paleontology.  One of my main goals here is to show that paleontology more than just dinosaurs. The website also features girls and boys of all colors in an inclusive environment working in the field, so all viewers can see themselves in this context.  


Question 12: Are there any fossils you’d like to work with that you haven’t yet?


DW: YES.  Shovel-tusked elephant!  I think an elephant with four tusks, like the gompotheres or Platybellodon is so cool.  I'd also like to work with pterosaurs and giant snake, like Titanoboa.  There were probably snake fossils around when I was working in Wyoming, but their bones are so delicate, they are hardly ever found.  Given how many small and medium sized mammals were out there that could serve as prey, paired with the hot, humid climate, there HAD to be large snakes around back in the Eocene.  It's just a matter of finding one.


Question 13: Do you ever get criticized on any of your work?  How do you handle it?


DW: Talk it out. Most disagreements I've experienced have been about whether or not to take a fossil out of the ground.  Collecting fossils early in the field schedule can sometimes be favorable because it seems like a good specimen and we have the means to collect it.  However, sometimes when it's early in the field season we decide to leave it there in favor of possibly finding an even better specimen int he field.  Sometimes we ultimately decide not to collect a particular fossil because doing so will be too much work/effort, or they're just too close to a major road to safely do so.  


Question 14: A common idea is that paleontology is just a “for fun” science, with no real impact or noticeable effect that helps the world.  Do you think paleontology has a bigger part to play to than this?  How?


DW: Yes, paleontology absolutely plays a bigger part.  First of all, the world needs more paleontologists because we need to understand how life on this planet developed over geologic time.  Second, and maybe even more importantly, is that paleontology is a gateway science for really young people to get interested in other sciences.  The world needs more doctors, energy engineers, and waste management engineers.  Toddlers don't roll out of bed interested in, let alone understanding, these things, but they are interested in paleontology.  If you want more people in these important science fields, medical, and engineering fields, paleontology is the way to get it.  Paleontology teaches kids how to think scientifically, how to collect and interpret data, how to form a hypothesis and so on.  Most kids interested in paleontology don't stick with paleontology.  They usually go on to other sciences as they get older and progress in school.


Question 15: Who was the first paleontologist you met?  How was that interaction?


DW: I first met a paleontologist when I was volunteering at a museum when I was eighteen years old.  Later on as I kept my interest, however, I did meet some really incredible people in the field.  John Alexander, from the Burke Museum in Seattle, Jim Kirkland, of the Utah Geologic Survey, and Richard Zakrzewski at Fort Hayes State University in Kansas (now retired) are probably the top three when it comes to people who have inspired me.  Also Christian Sidor.  I med John Alexander and Don Prothero at the AMNH when I was measuring Miocene rhino specimens for my graduate research.  


Question 16: What is your favorite prehistoric animal?  Was it different when you were younger? 


DW: When I was a really little kid my favorite was Brontosaurus. Now my favorite dinosaur might be Kentrosaurus. (which I chose for the logo on my website). This is probably because when I was younger my dad got me a book about dinosaurs and when I opened the book and noticed on the inside cover was a world map with dinosaurs illustrated over each continent.  I remember seeing what I now know was Kentrosaurus (which wasn't labeled in this book) placed over central Africa.  I remember immediately looking through the rest of the book for this awesome spiky dinosaur, but couldn't find it!  They mentioned Stegosaurus, of course, but it didn't match the image on the inside cover.  I felt ripped off.  When it comes to prehistoric mammals, I love rhinos, saber-toothed cats, and four-tusked elephants, like Stegotetrabelodon.  

Kentrosaurus by Christopher DiPiazza

Question 17: If you could use a time machine to go back and pick only one prehistoric animal to bring back from history and observe alive and in person, which would it be and why?


DW: Quetzalcoatlus.  I want to see an animal with a 45-foot wingspan take off.  I would love to see how it does that.  If you ever watched a large heron or eagle takeoff it is not easy.  I'm so curious to see how these gigantic pterosaurs achieved the same thing.  I'd also love to see a sauropod migration.  I try to imagine a herd of 30-40 ton animals all together in a group going back to their ancestral lands.  It must have been a sight to see.  


Question 18: Back to the time machine.  This time you can go back to any place and time period and have a look at what the environment was really like.  Which one would you pick and why?


DW: I'd have to go back and look at Antarctica when it was tropical.  I'd also want to see Antarctica when it was in transition from temperate to boreal.  There must have been a whole community of miocene mammals there that dealt with snow seasonally.  We know very little of this part in earth's history.  It would have had about 20 million years worth of evolution there we have never seen any trace of.  Marsupials with thick fur?  Cold-adapted monotremes?  Who knows?  


Question 19: Which is your favorite museum?  Why?


DW: The American Museum of Natural History in New York.  It has almost everything.  If you're looking for the biggest prehistoric science buffet (literally and figuratively) this is the place to go.  I could go there every week and always learn new things.  


Question 20: What hobbies do you have?  (Don’t have to be paleo-related.)


DW: I like to do pen and pencil illustration and woodworking.  The logo of my website of Kentrosaurus I illustrated.  I like to bake and am a foodie as well.


Gritty...

Question 21: What prehistoric beast do you think shares the most in common with Gritty?


DW: Back in the pliocene or late miocene there were probably species of primates that had long hair.  I refuse to believe that the longest haired primates alive today are the record holders.  So if there was a prehistoric monkey with extra long orange hair, that would be a reminder of Gritty.  

Sunday, December 13, 2020

Rutiodon: Beast of the Week

 This week we'll be checking out a prehistoric beast that was a crocodilian before crocodilians existed.  Take a look at Rutiodon carolinensis!

Rutiodon grabbing a late Triassic pterosaur (based on Caelestiventus) reconstruction in watercolors by Christopher DiPiazza.

Rutiodon was a carnivorous prehistoric reptile that lived during the late Triassic Period, between 237 and 208 million years ago in what is now the east coast of the United States, with fossils found in New York, New Jersey, and North Carolina.  From snout to tail Rutiodon shows variation among adult lengths,  ranging from about ten to as large as twenty-six feet.  The name, Rutiodon, translates to "wrinkled tooth" in reference to the grooves along the length of some of its teeth.  

Rutiodon belonged the family of reptiles called phytosaurs.  Phytosaurs are fascinating because they looked and likely behaved very much like modern crocodilians...but weren't even closely related to them!  In fact, modern crocodilians are more closely related to dinosaurs(including birds) and pterosaurs than they are to phytosaurs.  During the Triassic the ancestors of crocodilians were actually generally small, land-dwelling creatures.  It wasn't until the end of the Triassic, when phytosaurs went extinct, that the crocodile group appears to have taken advantage of that ecological niche and eventually evolved a very similar body plan for a very similar lifestyle. Despite the similarities, the most notable difference between phytosaurs, like Rutiodon, and crocodilians is the nostril placement.  Phytosaurs had their nostrils closer to the base of the skull, near the eyes, while crocodilians have their nostrils at the tip of the snout.  Both placements allowed the animals to breathe while mostly submerged underwater.  

During the time of Rutiodon, the true crocodilians were small land-dwellers.

Rutiodon likely spent most of its time in or near fresh water.  Its eye sockets and nostrils were both at the highest point of its skull so it would have been able to remain almost completely hidden in murky water while still being able to see and breathe.  This would have been a helpful adaptation if it was trying to get close enough to snatch prey as it drank at the water's edge.  Rutiodon also almost certainly ate plenty of fish and other aquatic animals and maybe even occasionally snatched careless pterosaurs perched on low-hanging branches or as they flew too close to the water's surface.  Rutiodon's teeth showed some diversity depending on their placement in the mouth which give us hints as to how exactly it fed.  The teeth at the very tip of the jaws were the longest, which could have concentrated more pressure to that point as the animal bit into struggling prey.  The needle-like teeth in the middle of the snout were more for holding on and making sure food didn't escape once bitten.  

Rutiodon skeleton at the American Museum of Natural History in New York.

Like modern crocodilians, Rutiodon was adorned with bony armor plates, called osteoderms.  This armor would have served as protection against predators when Rutiodon was still young and small, and possibly against other members of its own species if adults engaged in any kind of fighting over territory or dominance.  If modern crocodilians are any indicator of its behavior, then they probably did. 

References

Colbert, E. H. (1947). Studies of the phytosaurs Machaeroprosopus and Rutiodon. Bulletin of the American Museum of Natural History 88:53-96. 

Michelle R. Stocker (2010). "A new taxon of phytosaur (Archosauria: Pseudosuchia) from the Late Triassic (Norian) Sonsela Member (Chinle Formation) in Arizona, and a critical reevaluation of Leptosuchus Case, 1922". Palaeontology53 (5): 997–1022. 

Stocker, M. R. (2012). "A new phytosaur (Archosauriformes, Phytosauria) from the Lot's Wife beds (Sonsela Member) within the Chinle Formation (Upper Triassic) of Petrified Forest National Park, Arizona". Journal of Vertebrate Paleontology32 (3): 573–586.

Tuesday, November 24, 2020

Giraffatitan: Beast of the Week

Last time we did Brachiosaurus, now it's only fitting we cover its relative that everyone gets it confused with.  Enter Giraffatitan brancaiGiraffatitan was a sauropod dinosaur that lived in what is now Tanzania, Africa, during the late Jurassic period, about 150 million years ago.  This plant-eater was huge, amongst the largest land animals of all time.  The most well-studied specimens of Giraffatitan are of an animal that was about 74 feet long when it died, however, this animal's bones show it was still growing at the time.  Some estimate this dinosaur could acheive lengths of closer to 85 feet long from snout to tail.  The name, Giraffatitan, translates to "Giraffe Titan/Giant".  This is in reference to its long neck and front limbs which are superficially similar to those of the comparably puny and unrelated modern giraffe.

Giraffatitan brancai watercolor life reconstruction by Christopher DiPiazza.

This dinosaur's long neck and legs would have been used to help it gain access to more vegetation high in the trees, which it would have eaten using its chisel-shaped teeth lining the front of it's mouth.  Since it didn't have any teeth designed for chewing in the back of its mouth, Giraffatitan, like many sauropods, would have swallowed mouthfulls of foliage whole.  Unlike other kinds of sauropods like Apatosaurus or Barosaurus, Giraffatitan wouldn't have been able to rear up on its hind legs very easily because it's center of gravity was near its chest and shoulders, not its hips.  This anatomical characteristic is common to all members of Giraffatitan's family, called Brachiosauridae.

Giraffatitan skull on display at Museum fur Naturkunde in Berlin, Germany.  Note the nostril cavity on the forehead.

Another interesting characteristic of Giraffatitan's anatomy is it skull, which possesses nostril holes on its forehead that form a bony crest.  Scientists used to believe that Giraffatitan, along with all other sauropods, lived a semi-aquatic lifestyle and that the nostril placement was for snorkeling.  We now know this is false since the water pressure would likely prevent the dinosaur from comfortable breathing if its chest was that far underwater.  Another idea suggested that Giraffatitan would have had a trunk since modern mammals with high nostril placement, such as tapirs and elephants, have trunks.  This hypothesis is likely false as well because a sauropod's teeth were designed for grasping food and some fossilized specimens even show wear from it.  Why would it need a trunk?  Both elephants and tapirs have chewing teeth in the backs of their mouths.  According to the most recent studies, it is most likely that Giraffatitan would have had fleshy nostrils near the tip of its snout that connected to the nostril openings at the top of the skull in life.

Giraffatitan skeletal mount on display in Berlin, Germany.

Giraffatitan used to be called Brachiosaurus and was one of two known species within its genus.  In fact, most reconstructions labelled as "Brachiosaurus" are based on Giraffatitan remains.  The famous 
"Brachiosaurus" from Jurassic Park, for instance, was based on Giraffatitan. (although at the time the movie was made it was still considered a kind of Brachiosaurus.)  It was realized that the animal now referred to as Giraffatitan and the other animal that used to share a genus with it, Brachiosaurus altithorax, had enough morphological differences so the genus was split.  The biggest notable difference between these two giant dinosaurs is their midsections and tails.  Brachiosaurus had a longer, more robust torso and a longer tail while Giraffatitan was more compact with a shorter tail.  

Giraffatitan scapula (shoulder blade) on display in Berlin, Germany.  5'1" wife for scale.

References

Russell, D., Béland, P. and McIntosh, J.S. (1980). "Paleoecology of the dinosaurs of Tendaguru (Tanzania)." Mémoires de la Societé géologique de la France, 59: 169-175.

Taylor, M.P. (2009). "A Re-evaluation of Brachiosaurus altithorax Riggs 1903 (Dinosauria, Sauropod) and its generic separation from Giraffatitan brancai (Janensh 1914)." Journal of Vertebrate Paleontology, 29(3): 787-806.

Witmer, L.M. (2001). "Nostril position in dinosaurs and other vertebrates and its significance for nasal function". Science 293 (5531): 850–853. doi:10.1126/science.1062681. PMID 11486085.

Sunday, November 8, 2020

Brachiosaurus: Beast of the Week

 It's time to check out one of the most famous giant dinosaurs.  Make way for Brachiosaurus altithorax!

Brachiosaurus was a huge plant-eating sauropod dinosaur that lived in what is now Western United States during the late Jurassic period, about 153 million years ago.  It's genus name, Brachiosaurus, translates to "Arm Lizard/Reptile" because its arms were longer than its legs, and its species name, altithorax, translates to "Deep Chest" because of its particularly tall ribcage.  From snout to tail an adult Brachiosaurus is estimated to have been between 60 and 70 feet long and its head was held about 30 feet off the ground when standing.  

Brachiosaurus altithorax watercolor life reconstruction by Christopher DiPiazza.

Brachiosaurus was originally only known from a few bones, including the pelvis, some vertebra, and limb bones.  Over the years, however, more fossils from this dinosaur have been unearthed from multiple individuals that altogether give us a relatively complete skeleton. Sauropod skeletons are notorious for being found incomplete because they're so large and therefore their bones were more prone to getting eroded, carried away by predators, or scattered after death.  Fossilization most commonly happens when the animal's body is buried rapidly and completely after death.  Therefore it's takes a lot more forces of nature for this to happen to a large animal than a small one.

Brachiosaurus, as stated above, is famous for having longer arms than legs, which makes its family, brachiosauridae, unique among dinosaurs.  In addition, its arms were placed farther below its spine than its legs, causing it to be even taller in the front.  This unusual posture allowed Brachiosaurus to reach especially high with its already long neck to take advantage of leaves on the tops of trees that even other sauropods couldn't easily reach.  Unlike other sauropods, brachiosaurids had proportionally shorter back legs, and tail which were held relatively low because of this sloping build.  Having shorter back limbs also would have highly limited Brachiosaurus' ability to rear up on its hind legs, which other kinds sauropods, like the diplodocids, likely were able to do more easily.  Despite what that iconic scene in Jurassic Park* may show you, real brachiosaurs likely very rarely stood on just two limbs, and if/when they did, only for extremely short periods of time, like to mate or possibly intraspecies combat.  Since Brachiosaurus' center of gravity was in its torso, not its hips, that kind of posture would put extreme pressure on its back end which could seriously injure the dinosaur.  All things considered, if an animal could reach thirty feet in the air from a standing position...rearing up probably wasn't necessary often.

Brachiosaurus' neck bones were relatively rigid closer to the skull, but the part of the neck closest to the shoulders would have had more flexibility.  This means that despite its very front-loaded posture, it could still bend its neck so its head was close to the ground if it need be.  This would have been necessary when Brachiosaurus needed to drink, or maybe even eat certain kinds of low-growing plants at times.  It wouldn't have needed to bend or spread its front limbs in order to achieve this either.  The neck bones, along with many of its other bones, were hollow and would have been filled with air sacs in life.  Some of the spaces around the bones (which can be inferred by the negative space around the edges of the vertebra) was also filled with air sacs in life.  These structures were connected to the animal's respiratory system and allowed the body to be more efficient in distributing oxygenated air to where it needed to go.  This also made the animal much lighter for its size, so moving that neck around wouldn't have drained as much energy as it would have appeared.  

Brachiosaurus could have lowered its head down to ground-level relatively easily when it wanted to.

The skull of Brachiosaurus was found and published in 1998.  It had a relatively long snout with chisel-shaped teeth concentrated to the front of the mouth, an adaptation for stripping leaves off branches.  It had no teeth in the back of the jaws, implying it simply swallowed all its food and relied on its insides to do all the work of breaking everything down.  It is possible dinosaurs like Brachiosaurus swallowed rocks, which would stay inside the stomach for extended periods of time, which would have helped mechanically break down its food as they mixed around in the stomach, called gastroliths.  Brachiosaurus' eyes were set high, towards the rear of the skull and the naris (holes in the skull where nostrils were) are elevated in a sort of bony crest between the eyes.  For a long time it was thought that Brachiosaurus had its nostrils high on the head exactly where these openings are on the skull, but it is more likely that these openings were connected to soft tissue that placed the nostrils closer to the front of the snout.  The evolutionary reasoning why Brachiosaurus, and many other sauropods had these openings on the top of the skulls, if not the true placement of the nostrils, is still somewhat of a mystery.  Some have suggested that this area was a space where air could flow through and help keep the blood in the animal's head and brain from overheating.

Photograph of the mostly complete (partially reconstructed) Brachiosaurus skull from Carpenter's 1998 paper.

As an adult, Brachiosaurus likely had few to no predators to worry about.  It was just too big.  When imagining it in its environment I sometimes stop thinking of it as an animal and more as a roaming force of nature more than anything else.  That being said, young Brachiosaurus were probably easier prey for all sorts of predators from the moment they hatched for years until they hit a certain size.  These younger animals probably relied on camouflage or possibly living in groups to minimize their chances of becoming another animal's meal.  

Special thanks to Dr. Heinrich Mallison for lending his sauropod expertise during the process of me writing this post!  See you next time!

*The dinosaur in Jurassic Park that's referred to as Brachiosaurus is actually based on a close relative called GiraffititanGiraffititan used to be considered a species of Brachiosaurus back when the film was made, so it being referred to as such in 1993 wasn't wrong.  

References

Carpenter, Kenneth, and Virginia Tidwell. 1998. Preliminary description of a Brachiosaurus skull from Felch Quarry 1, Garden Park, Colorado. Modern Geology 23:69-84.

D'Emic, M. D.; Carrano, M. T. (2019). "Redescription of brachiosaurid sauropod dinosaur material from the Upper Jurassic Morrison Formation, Colorado, USA". The Anatomical Record303 (4): 732–758. 

Riggs, E.S. (1903). "Brachiosaurus altithorax, the largest known dinosaur"American Journal of Science. 4. 15 (88): 299–306.Taylor, M.P. (2009). "A re-evaluation of Brachiosaurus altithorax 

Russell, D. A. (1989). An Odyssey in Time: Dinosaurs of North America. Minocqua, Wisconsin: NorthWord Press. p. 78. ISBN 978-1-55971-038-1.Witmer, L. M. (2001). "Nostril position in dinosaurs and other vertebrates and its significance for nasal function". Science293 (5531): 850–853.

Sunday, November 1, 2020

Lycaenops: Beast of the Week

 This week we will be checking out a prehistoric creature that bears a striking resemblance to some modern-day animals.  Let's check out Lycaenops!

Watercolor life reconstruction of two Lycaenops angusticeps by Christopher DiPiazza.

Lycaenops was a meat-eating synapsid (wide group of animals that includes mammals) that lived in what is now South Africa during the Permian era, between 271 and 251 million years ago.  The genus name translates to "Wolf Face" because of it's relatively long snout and prominent canine-like fangs, which caused this creature to superficially resemble wolves, and other modern canids despite not being closely related.  From snout to tail, Lycaenops measured about three feet long, or a little under one meter.  There are several species within the genus, Lycaenops, which accounts for the relatively wide range of time in which this genus existed.

Lycaenops was part of a widely successful group of vertebrates that lived during the Permian, before the first dinosaurs, that are casually referred to as "mammal-like reptiles" even though they weren't mammals...and they weren't really true reptiles either.  They were somewhere in between and no living members exist today, which makes it even more difficult to visualize what they would have been like when alive.  Within this extremely expansive group, Lycaenops, was specifically a member of the gorgonopsid family.  These meat-eating synapsids all long, rectangular skulls with very long, curved fangs on the top and bottom jaws, in the same place that canines would be on some mammals, like dogs, bears, and cats.  This is an amazing example of convergent evolution, since these gorgonopsids were not directly related to any of these carnivorous mammals.  

Lycaenops ornatus skeletal mount on display at the American Museum of Natural History in New York.

Lycaenops probably specialized in hunting smaller prey.  The Permian was home to no shortage of small reptiles, amphibians, and other synapsids, so it is likely Lycaenops had a pretty expansive menu to choose from.  It's eye sockets are relatively large so it probably had decent vision, and its limbs were also pretty long in proportion to its body, which it appears to have carried under its body more so than many other reptiles and synapsids at the time, which had more sprawling postures, like today's lizards and crocodilians.  This combination of features probably gave Lycaenops its edge when pursuing meals when it was alive.  

It is important to keep in mind that Lycaenops lived right up to the very end of the Permian era, which is marked by a massive global extinction event, more destructive than the one that wiped out most of the dinosaurs millions of years later.  It was this extinction that actually leveled the playing field and allowed the dinosaurs to even evolve in the first place.  Because of this it is worth noting that Lycaenops and its relatives were extremely successful animals, and likely would have kept flourishing if it wasn't for that catastrophic event.  

References

Broom 1925 : On some carnivorous therapsids. Records of the Albany Museum, vol. 3, n. 4, p. 309–326.

Gebauer, E.V.I. (2007). Phylogeny and evolution of the Gorgonopsia with a special reference to the skull and skeleton of GPIT/RE/7113 ('Aelurognathus?' parringtoni(Ph.D. thesis). Tübingen: Eberhard-Karls Universität Tübingen. pp. 1–316.

Saturday, October 31, 2020

Halloween 2020: Thirteen More Monsters

 Six years ago I thought it would be neat if I drew pictures of thirteen dinosaurs and other prehistoric beasts that are named after monsters, horror, mythology, and generally spooky things...as those things.  The result was fun and I ended up doing it again with thirteen more the next Halloween.  If you have not seen those I recommend checking them out here and here.  If you've already done that now it's time to check out the long awaited, third installment!  

Below you will see a silly drawing I created of thirteen strange monsters.  They're each meant to represent a specific prehistoric creature that is named after something from mythology, horror, or something else generally spooky.  This could refer to the genus OR the species name.  Take a moment to check them out and try to figure out which taxa each of these monsters is meant to represent.  Then, keep scrolling to see the answers and a brief explanation!  Have fun!


Give them all a good look?  Think you correctly identified all of them?  When you're ready simply scroll down for all the reveals!  You may notice that a few of the names are clickable.  This means that I've covered that particular beast as a "Beast of the Week" on this website before.  That link will take you to a page just about them with more information!

Garudimimus

Garudimimus was an ornithomimid dinosaur that is named after Garuda, a creature from Buddhist mythology that resembles a cross between humans and large colorful eagle-like birds.  

Sollasina cthulhu

Sollasina was a relative of modern sea urchins that lived 430 million years ago that had scaly arms surrounding a small mouth.  Its species name is after the elder god from H.P. Lovecraft's stories, Cthulhu.

Livyatan

Livyatan was a prehistoric whale, related to modern Sperm Whales, with huge pointed teeth on both its upper and lower jaws.  It's named after the Leviathan, a gigantic sea monster from biblical mythology. 

Lycaenops

Lycaenops was a gorgonopsid, a kind of synapsid(relative of mammals) that lived during the Permian era.  It's genus name translates to "wolf face".  

Oksoko

Oksoko was a theropod dinosaur in the oviraptorid family.  Three specimens, including three skulls were found  closely together, inspiring its genus name after the oksoko, a mythical three-headed eagle from Eastern European mythology.  

Balaur 

Balaur was a small, bird-like dinosaur that lived in what is now Romania.  It is named after Balaur, a many-headed dragon from Romanian folklore.

Eucritta

Eucritta's genus name translates to "True Creature" in reference to the Creature from the Black Lagoon.  The species name, melanolimnetes, translates to "black lagoon", confirming this connection even more. This is because, like the famous movie monster, this early relative of amphibians had different traits of both land and aquatic animals.  

Skorpiovenator

This was a meat-eating dinosaur, related to the more popular, CarnotaurusSkorpiovenator's genus name translates to "Scorpion Hunter" because there were so many wild scorpions present at the digsite where its bones were unearthed.  

Ogresuchus

Ogresuchus' bones were discovered near a nesting ground of baby sauropod dinosaurs and it was believed this relative of modern crocodilians was hunting them at the time.  The genus name translates to "Ogre Crocodile" because of child-devouring ogres from folklore and fairytales.  

Zuul

Zuul was a ankylosaurid (armor and tail clubs) dinosaur that lived in what is now Canada during the late Cretaceous period.  Its genus name is because its horns and low, wide skull make it resemble the monster, Zuul the Gatekeeper of Gozer, from the 1984 Ghostbusters movie.  

Taniwhasaurus

Taniwhasaurus was a mosasaur (prehistoric marine lizard) that swam in oceans over what is now New Zealand.  It's name is in reference to the taniwha, a monster from Mouri mythology that lives in rivers and other bodies of water that are sometimes revered and respected, but other times feared.  

Smok

Smok was a large archosaur (part of the group that includes both dinosaurs and crocodilians) that lived during the late Triassic period in what is now Poland.  Its genus name is after the famous dragon from Polish folklore who was famous for living in a cave under a hill.

Zilantophis

Zilantophis was a prehistoric snake named after the zilant, a dragon-like monster from Russian mythology with a long, serpentine tail, wings, and legs of a bird.  


I hope you enjoyed the latest installment of my fusing paleontology with monsters and mythology.  I find it particularly neat since prehistoric animals still inspire us to imagine and design new imaginary beasts to this day in art, entertainment, and video games just to name a few examples.  Can you think of a prehistoric beast named after a monster that I haven't included yet?  Leave it in the comments below and maybe I'll include it next Halloween!