Deinonychus antirrhopus (© crownedrose)
➛ Lived during the Cretaceous Period.
➛ A member of the Dromaeosauridae family.
➛ Most likely covered in feathers, but we have no skin/feather evidence currently for Deinonychus.
➛ The top of its head reached a little over halfway up an average human’s body, and generally reached lengths of 11 feet.
➛ As shown, it features a sickle claw on each hind foot.
➛ Deinonychus is a very important dinosaur because of John Ostrom’s work with the theropod, leading to the Dinosaur Renaissance.
➛ These photos were taken by me at The Field Museum in Chicago.
Daspletosaurus (© crownedrose)
- Lived during the Cretaceous Period.
- A member of the Tyrannosauridae family.
- Fossils have been found in North America.
- Similar to T. rex, Daspletosaurus is commonly mistaken to be its North American cousin.
I know I have to get some more TOTD posts up, but I lost the list of requests. These posts do take time to write, and I’m not on Tumblr or my Mac 24/7 to write them daily (as you guys have figured out by now haha).
But I’m going to make this the official request post. Keep your requests for theropods in the Mesozoic, please. Here’s that mandatory question mark so you can answer?
Random Dinosaur Fact Of The Day:
Did you guys know we only have the head of Irritator challengeri? The rest of the skeleton is based off other Spinosauridae members. Even then, we don’t have the complete skull, and it was (illegally sold and) tampered with as well by fossil dealers.
Look! A new T.O.T.D. post. I know what you’re all saying to yourself: “Finally!”. I promise to have more frequent posts now that my schedule is calm for the time being, so enjoy! Spinosaurus aegyptiacus is a large (theorised to be the largest ever!) theropod that lived in North Africa during the Early - Late (but really more like middle) Cretaceous. Meaning “Egyptian spine lizard”, it was a partial skeleton (mainly) discovered and described by Ernst Stromer back in 1912 in the Bahariya Formation of Egypt. Everyone knows this guy mainly because of his role as the antagonist in Jurassic Park III back in the early 2000’s. Below is information you may and may not have known about Spinosaurus.
⁌ Spinosaurus aegyptiacus is a unique animal, belonging to the Spinosauridae family. Remember my earlier T.O.T.D. post on Baryonyx? They look pretty similar, don’t they? Well, yes, they have similar skulls, but Spinosaurus has something very unique that Baryonyx lacked, and that is those amazing dorsal vertebrae extensions (known as neural spines) which grew to lengths of around 5 feet! How tall are you? Maybe 5’ 4”? Yep, you’re the height of solely those sail spines. Now think about how big that means for Spinosaurus overall. What they were for is still not truly known. It could have been used for temperature regulation or display (potential mates, steering off other males, etc) as a sail, which most artists and media depicts, but some even think it could have formed a (…big) hump to make the animal look bigger. Me? I’m with the sail theory.
⁌ The skull, like Baryonyx, was shaped very crocidilian-like, and we’ve found evidence of a partial aquatic life. Not 100% aquatic, but the majority says aquatic when isotopes in the teeth are studied. Their skulls were most likely built to just have the tip of the snout in the water, waiting for the right time to strike! The nasal cavity lay higher on its head to stay above water as well, most likely. Very nice evolutionary tactics you’ve developed there, Mr. Spinosaurus! As with Baryonyx, these animals probably fed on fish and other marine animals a decent amount of the time (but not 100%), which was a more specialised diet compared to typical theropods. They shared Northern Africa with Carcharodontosaurus as well (and of course others), and with both theropods having (mainly) different feeding styles, this may have helped the two co-exist better off than others.
⁌ Much of Spinosaurus is based on theory, other Spinosauridae skeletons found, and photos/information of destroyed bones. Yep, you heard right! Back in the early 1900’s, a palaeontologist named Ernst Stromer found Spinosaurus in the Egyptian desert (plus others!), and brought them back to his museum in Germany. When WWII came around, the museum was bombed and his fossils of Spinosaurus destroyed. It’s pretty hard to make concrete judgements on fossils in a photo, which is why we then look to other Spinosauridae members like Baryonx or Suchomimus to help piece together what Spinosaurus may have fully looked like. We’re luckily finding new material to work on, but it’s always a shame to have such beautiful and precious fossils destroyed.
⁌ There have been two specimens described since the first discovery. Of course, there’s the more well known Spinosaurus aegyptius, and then there’s Spinosaurus maroccanus. Could they actually be the same species? Well, as it was discussed in a lecture I attended not too long ago about the Bahariya Formation (+ more), it’s always hard to 100% confirm either way when you don’t have full skeletons. Of course, Allosaurus and Spinosaurus are two totally different theropods, but when it gets down to the two described spinosaurs which are from partial skeletons (and some that are just fragments), we can’t be sure until more is discovered. Even in today’s world with full (and multiple) skeletons of ceratopsids, there’s still the debate between some on Torosaurus and Triceratops legitimacy as separate genus! Palaeontology is all about putting pieces together and solving the puzzle, but it can be difficult at times.
⁌ There are points I didn’t cover in this post, but are similar in my T.O.T.D. post on Baryonyx. Why is there similar information for these guys? Well, it’s because - again - some of Spinosaurus is based on other Spinosauridae members like Baryonyx, so you can check out Baryonyx to read about those big thumb claws, the notches in the skull, etc.
If anyone would like more information on dinosaurs (esp. theropods) or Spinosaurus, just send me a message! These posts are meant to give you guys known and not-so-known information written short and simple (well - my definition of short and simple!), so if you want more info on theropods, just let me know. I’m always willing to answer questions for the curious minds out there. I hope you all have enjoyed reading this, and be sure to keep a look out for future T.O.T.D. posts!
Theropod Of The Day Links:
I actually have a Theropod Of The Day post done! I know, that’s a headliner right there, haha.
It’s on Spinosaurus, which will be posted later today. I have other posts in the works, including many requests.
I apologise again for the lack of TOTD posts recently. But when real life palaeontology and geology call me to lectures, events, and digs, I can’t say no.
I’ll reblog past TOTD posts today for anyone who has missed those, and just keep a lookout for Spinosaurus later today!
It would take forever, but then again that means the TOTD posts won’t end quickly! Haha. Sure thing! I have them up on my “requested” list so that they will take higher priority than others on my general “to-do” list.
I did, a little while back, make a post about the differences because someone had asked in a reblog of mine. I can elaborate on it all as well in the future posts if you’d like!
As well, my friend Ryan (tyrannoraptora) did a great post on Deinonychus and stuff related to the raptors in JP. He also posted about raptor biomechanics, and theropod biomechanics are AWESOME!
Of course! I have done a TOTD post on Baryonyx if you’re interested in looking at that - seeing as they are both members of Spinosauridae. I’ve done one as well on T. rex, and have smaller bits of information for other theropods in my TOTD tag. I have a master-list as well showing what I’ve covered so far when it comes to “official” posts. Browsing through my TOTD tag will lead to everything covered so far, so check that out if you’re interested.
For everyone as well, I’m sorry I haven’t had time to publish new ones! As I’ve stated before, my schedule can get insane some weeks. I’ll be working on new TOTD posts this weekend to have them published ASAP. I do appreciate the patience because I know many of you have requested animals to be covered! I haven’t forgotten, but these posts do take up some time for me to write, and I like to do them in one sitting; right now it’s just finding that amount of time to have at my disposal.
I’ve got other things as well, but those are some key topics I’ll be talking about. If you have anything you’d like me to cover, let me know! Have a look through my past posts as well on: science, geology, palaeontology, paleontology (yes I use both tags), dinosaurs, & Theropod Of The Day.
A member of the Spinosauridae family, Baryonyx (meaning “heavy claw”) is a specimen which sometimes is confused with the better known dinosaur, Spinosaurus aegyptiacus. It was first discovered back in the 1980s in England by an amateur palaeontologist who saw a claw sticking out of the side of a pit! How lucky and cool is that?! Here’s some other information below on what we know about Baryonyx.
⁌ Baryonyx walkeri lived during the Early Cretaceous Period, roaming parts of what is now the United Kingdom and Europe. With a crocidilian-like snout, three digit claws (one being a massive thumb claw), and perhaps measuring over 30 feet long, Baryonyx was one of the few theropods known to diet on fish a majority of the time.
⁌ Let’s talk about that head for a moment. The structure is very different compared to large theropods - more like what you see in crocodiles - which leads us to believe this skull was specifically evolved for a certain type of prey. Just look at that elongated skull! Baryonyx had a lot of cone-shaped teeth (over 90!), and two third’s of those teeth were set in the lower jaw. Also, the roots were longer than the visible teeth you see sticking out of the jaws! Then there’s my favourite feature in the Spinosauridae family: that notch in the maxilla. Just like crocodiles, this special formation is a great tool used to keep prey from escaping.
⁌ If you study the head, you’ll notice the nasal opening is farther back on the skull compared to other theropods - and as it is theorised for the Spinosauridae family that they’d leave the tip of their mouths in the water, awaiting prey to lingering a bit to close. For Baryonyx, we’ve found scales and remains of fish (Lepidotes) and even Iguanodon remains in the stomach area of Baryonyx. Pretty awesome, right?! Whenever remains of a dinner are found in a dinosaur’s cavity, this truly gives us great insight on their diets. Finding these remains as well are rare, so every find is precious.
⁌ Did you know that we do not have a full skeleton for any one Spinosauridae family member? Baryonyx was found with around 70% of its skeleton, and Suchomimus is the most completely known, which has helped us to “build” what other spinosaurids could have looked like. Irritator for example is only known by a partial skull and a few bits and pieces.
⁌ Suchomimus is thought to perhaps be Baryonyx due to the similarity between vertebrae, but some are skeptic of this theory. With more fossils found, more evidence, and more research, one day we’ll be able to settle any colliding thoughts.
⁌ Baryonyx has this awesome and massive claw as the thumb on its forelimbs, which could have been to help stab/grasp prey.
⁌ Baryonyx, like other spinosaurids, have been found to have lived a semiaquatic life, due to the testing of stable isotope ratios in the teeth, finding similarities in what is found in turtles and crocodiles. This helps the theory of their diet to be composed of (mainly) fish, along with living in a different kind of habitat, co-existing with other large theropods would be less-dramatic.
Again, everyone, thanks for dealing with my hectic schedule and waiting for my next T.O.T.D. post! The past week has been very busy and full of events/lectures with some of the top palaeontologists out there - so think of my time away from Tumblr as beneficial to the upcoming T.O.T.D. posts seeing as all your favourite dinosaurs (and non-dinos) were discussed! If anyone would like more information on any dinosaurs (esp. theropods) or Baryonyx, just send me a message! These posts are meant to give you guys known and not-so-known information written short and simple, so if you want more info on theropods talked about in these posts, just let me know. I’m always willing to answer questions on theropods for the curious minds out there. I hope you all have enjoyed reading this, and be sure to keep a look out for future T.O.T.D. posts!
Theropod Of The Day Links:
It’ll be on Baryonyx! Woo! I just finished the post, and now I’m going over it just to make sure I covered what I wanted, and I’m also going back over notes I took when I attended the Palaeo event with Thomas R. Holtz, Jr. talking about theropods, and a small section on Spinosauridae.
Keep a lookout, guys! It’ll be posted very shortly.
Tyrannosaurus rex may as well be the most famous dinosaur to have ever walked the Earth. Its name means “tyrant lizard” in Greek, and rex is “king” in Latin which was pinned by Henry Fairfield Osborn back in 1905, and the massive theropod sure lives up to its name! Below is some interesting information about T. rex for all to enjoy.
⁌ T. rex lived during the Late Cretaceous Period (67-65 Mya) as many know, roaming what is now the western parts of the United States of America and Canada. They measured to be slightly over 40 feet long at maximum, with powerful and elongated hind legs that show an ability to allow a decent speed for such a robust animals. There’s also the thick tail to help with balance, and the iconic (but short) S-shaped neck you see in theropods.
⁌ Contrary to popular belief, T. rex had forelimbs that were not useless. Theories have been brought to the table that they were used during mating rituals, or perhaps to hold down prey (dead or alive). Studying these specimens, T. rex forelimbs show a considerable amount of muscle attachments, making these forelimbs much stronger than previously thought; perhaps being able to curl over 400 pounds with each two digit hand! Not so wimpy anymore, right?
⁌ The tyrannosaur above is nicknamed “Black Beauty” because of the magnesium rich (and well preserved) skeleton, which is on display at the Royal Tyrrell Museum in Alberta, Canada.
⁌ Many know and have heard of Tyrannosaurus “Sue”, which is my favourite dinosaur skeleton in the world! She is the largest, most complete, and best preserved Tyrannosaurus rex ever discovered. Her skeleton has given us an endless amount of information towards the life and biomechanics of tyrannosaurids, and dinosaurs in general of the Mesozoic. You can read extra information I’ve written up about Sue here.
⁌ Unlike their depiction in Jurassic Park, Tyrannosaurus rex had binocular vision, which gave them great eyesight to hunt and scavenge for their prey. If you look at their skull, it is shaped like a triangle; the front of the skull is slender which then widens out to the back of the skull. This structure helped T. rex to have this vision, which suggests that it was a hunter. Many years ago it was thought T. rex only scavenged for food, but the hunter/scavenger debate is one that still goes on to this day in palaeontology, plus the theories of Tyrannosaurus engaging in cannibalism is on the table!
⁌ Ever heard of their teeth being called ‘bananas’? Tyrannosaurus had teeth with heterodonty, which means that their teeth changed shape depending on their position in the jaws (just like us)! Everyone knows the teeth T. rex had, which are massive, thick with reinforced ridges, and shaped like bananas which in tandem with the jaw power of T. rex, made for a deadly crushing bite. The premaxillary teeth at the front of the jaws helped as well for them to not break off during feeding due to their shape (and those ridges!). T. rex as well also replaced teeth, just like sharks do. We’ve found this out because of well preserved fossils that show new teeth coming in around full grown ones.
⁌ Their skull is one to be reckoned with, evolution having a field day to make for a powerful killer. Unlike other theropods, T. rex had a U-shaped upper jaw at the tip, strengthening its power to create bone crushing jaws which could deal with much stress in tearing off meat. Having such a massive skull would be heavy, but luckily (like other theropods), T. rex had many ways to lighten the weight by having large openings in the skull, along with certain bones showing to be fused and have skeletal pneumaticity. Read more about theropod skull comparison here.
⁌ The growth rate of T. rex was very fast, and one of the most changing during their lifetime. If you compare a youngster and adult tyrannosaur, you will see how much they morph. From having knife-like teeth and elongated heads when young, they grow up to have a much wider and robust head with those banana teeth like I stated above. Because of this dramatic change, some discoveries of young tyrannosaurs are thought to be a new genus of tyrannosauridae (ever hear of Nanotyrannus?). Many still debate whether or not Nanotyrannus (and even other tyrannosaurs) is a new genus, and more research is still being done to weave out these questions.
Also, I just want to end this post with a big thank you to everyone who has encouraged me to write this series, and for reading my ridiculously long posts! I tend to get very excited when I write these up, and I tried my best not to go too in depth on every aspect of Tyrannosaurus rex, though it all is extremely interesting. If anyone would like more information on T. rex - like locomotion, anatomy, feeding habits, fossil history, etc - just send me a message! I’m always willing to answer questions on theropods for the curious minds out there. I hope you all have enjoyed reading this, and be sure to keep a look out for future T.O.T.D. posts!
Theropod Of The Day Links:
This will be a nice key for any dinosaur you’re looking for straight away. Listed below are the theropods that have been written about on my blog. If you have any questions or theropod suggestions, send me a message!
So I just wanted to say I read and appreciate all the feedback I received for the T.O.T.D. question! I’ve taken into account everything you all said and am trying a few things to make it not so tl;dr but also not cutting out everything I wrote. For me personally, I love reading long and detailed posts, but I do understand others aren’t as into it when it comes to that aspect. The T. rex post will be posted today! I’m doing a little editing to make it more “dashboard friendly”. I can say it will not be edited down to a few sentences, but I may even bold a few important facts for those who do not want to read the entire thing. I’ll see how I feel about it, but I sure hope in the end that everything I’ve written will be read!