Episode 500: Raptor Renaissance!. This historical past of dromaeosaurs (higher often called raptors). Plus an A to Z information of the most typical dinosaur phrases and inside jokes from our first 500 episodes.
A few of our greatest raptor sources (and a few information):
- Dromaeosaurs have many fowl like options of their shoulders, wrists, and feathers supply
- Each with trendy raptors (birds of prey) and dromaeosaurs the foot is the lethal weapon supply
- Utahraptor was found across the time the film Jurassic Park got here out, extra just lately a brand new large block of Utahraptors was discovered supply
- Paleontologist Bob Bakker tells a compelling story of a Utahraptor by means of her eyes in his novel Raptor Pink supply
- Paleontologist John Ostrom named Deinonychus in 1969 (which additionally has ties to Jurassic Park) supply
- “The primary definitive dromaeosaur with a fairly full skeleton ever discovered within the US” is nicknamed “Julietraptor” supply
- A listing of all of the dromaeosaurids AKA “raptors” (as of 2012) supply
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The dinosaur of the day: Deinonychus revisited
- Dromaeosaurid theropod that lived within the Early Cretaceous in what’s now the U.S. (Montana, Utah, Wyoming, Oklahoma)
- Discovered within the Cloverly Formation and Antlers Formation
- Tooth that will belong to Deinonychus have additionally been present in Maryland (Potomac Formation)
- Seemed much like Velociraptor, however a bit greater
- Estimated to develop as much as 3.4 m (11 ft) lengthy
- Estimated to weigh as much as 100 kg (220 lb) primarily based on the femur and humerus (thigh bone and higher arm bone)
- Walked on two legs
- Had a triangular, broad cranium and slim snout
- Had massive fingers with three claws
- In all probability coated in feathers, primarily based on it wanting like a fowl and being carefully associated to different raptors (the place feathers have been discovered, comparable to Microraptor and Velociraptor—quill knobs discovered on the arm of Velociraptor)
- No direct proof of getting feathers, but
- Had massive sickle-clawed second toe (for slicing or slashing, not designed for greedy or digging)
- Second toe was “tailored solely for predation”
- Different toes round it helped with standing and shifting
- Kind and solely species is Deinonychus antirrhopus
- Genus title means “horrible claw”
- Genus title refers back to the massive, sickle-shaped claws on its second toes
- Species title antirrhopus means “counter stability” and refers back to the stiff tail that will have helped it
- Nevertheless, one specimen of Velociraptor discovered later had a tail that curved and should have been capable of bend to the edges
- Fossils first present in 1931 close to Billings, Montana
- Barnum Brown was main a workforce
- Principally targeted on Tenontosaurus on the time however talked about the Deinonychus fossils have been “encased in lime troublesome to organize”
- Informally named it “Daptosaurus agilis” and began to work on it, however didn’t end it
- In the summertime of 1964, John Ostrom led an expedition with Yale’s Peabody Museum of Pure Historical past close to Bridger, Montana (Cloverly Formation)
- Over two summers discovered greater than 1,000 bones, from a minimum of three people
- Arduous to know which bones belonged to which particular person, so laborious to know precisely what number of people
- Kind specimen (holotype) of Deinonychus was only a left foot and partial proper foot (too laborious to know which bones belonged to that particular particular person)
- Kind specimen had a strongly curved sickle claw
- Different specimens weren’t as strongly curved
- Could possibly be from particular person variation
- Additionally discovered vertebrae, almost full fingers, elements of the cranium, foot bones, elements of the shoulder, elements of the tail, and extra
- Later, Ostrom and Grant Meyer analyzed the fossils, in addition to the “Daptosaurus” and located all of them belonging to the identical species
- “Daptosaurus” was solely partly ready, however not studied
- Ostrom stated “it is just by likelihood” they’re included within the examine
- Partly due to Dr. Edwin H. Colbert
- Named all of them Deinonychus antirrhopus in 1969
- In 1969, Ostrom, when he named Deinonychus, wrote: “Among the many essential discoveries made was that of the spectacular little carnivorous dinosaur described right here—an animal so uncommon in its diversifications that it undoubtedly will likely be a topic of nice curiosity and debate for a few years amongst college students of natural evolution”
- “On the very second of discovery, it was evident from the few fragments uncovered on the floor that we had stumbled throughout one thing very uncommon and fairly in contrast to any beforehand reported dinosaur”
- Ostrom revealed a pair monographs on Deinonychus
- Extra fossils present in 1974 to assist fill in among the gaps (together with within the hip and pubis space)
- Had extra of a fowl hip (backwards dealing with)
- Ostrom’s description of Deinonychus result in the Dinosaur Renaissance (Sixties to Nineteen Eighties-ish the place scientists began seeing dinosaurs as extra energetic and agile once more, as a substitute of sluggish, lumbering reptiles)
- In 1969, Ostrom wrote that Deinonychus was proof that dinosaurs have been energetic (all primarily based on the foot)
- “In my view, the foot of Deinonychus is maybe essentially the most revealing little bit of anatomical proof pertaining to dinosaurian habits and capabilities to be found in lots of many years. Grandiose statements of this type are, in fact, simply rejected, however the useful implications of the pes of Deinonychus should not so simply discarded—particularly in view of the opposite exceptional diversifications of this animal. Deinonychus should have been something however “reptilian” in its habits, responses and lifestyle. It should have been a fleet-footed, extremely predaceous, extraordinarily agile and really energetic animal, delicate to many stimuli and fast in its responses. These in flip point out an uncommon stage of exercise for a reptile and recommend an unusually excessive metabolic fee. The proof for these lie mainly, however not solely, within the pes.”
- Ostrom additionally wrote:
- “It must be fairly apparent that this machine couldn’t be used until the animal stood on one leg. It’s also apparent that the usage of this construction necessitated vital agility and maybe even violent exercise whereas standing on that one limb.”
- Deinonychus was an energetic meat eater
- Ostrom in 1969 stated it was a “flesh-eater and nearly actually a predator”
- Sharp enamel, lengthy arms with claws on the fingers, stiff tails, and sickle-like claws on the second toes all would have helped
- A examine earlier this 12 months, in 2024 by Tse, Miller, and Pittman discovered Deinonychus had a narrower cranium, had comparatively excessive chunk drive/comparatively sturdy chunk in comparison with different raptors
- Had a tall, brief cranium
- Gradual, sturdy bites
- However, excessive pressure on the cranium
- Might go after massive prey, however cranium is comparatively much less proof against chunk forces than different dromaeosaurids
- Could possibly be it used its neck muscle tissues to tug again on prey, or possibly had a large gape (might open its mouth extensive)
- Perhaps used its arms for greedy at prey or clutching objects towards its chest
- Ostrom in 1969 laid out the concept Deinonychus caught and held prey in fingers after which disemboweled it with its foot claws (which might require it stands on one foot whereas ripping the flesh with the claw of the other foot)
- Ostriches and cassowaries could cause critical damage with the big claws on their interior toes
- One paper in 1958 by Gilliard “famous that the cassowary can simply sever an arm or disembowel a person with its lengthy sharp claws on the interior toes”
- One other paper in 1962 by Austin stated the “ostrich prefers to run, however when compelled to battle slashes out with highly effective kicks able to ripping open man or lion”
- Stored its sickle claw off the bottom, and walked on its third and fourth toes as a substitute
- Claws would have been even bigger in life (coated in keratin)
- Initially thought to chop and slash with claws
- Later thought to stab at its prey
- More moderen research discovered the claws have been good for climbing (so might climb on to prey, then pin it down and chunk into it)
- Might have killed prey by leaping on to, gripping tightly with its claws, and begin to eat the animal whereas it’s nonetheless alive (after which finally it dies from shedding blood and organ failure)
- Often called the Raptor Prey Restraint (RPR) speculation
- Based mostly on evaluating the ft and legs of dromaeosaurs to trendy birds of prey (much like eagles and hawks, based on Denver Fowler and others)
- Nevertheless, foot energy from its shorter ft (had brief metatarsus or higher foot bones) could be extra much like owls
- Arms could have been coated in lengthy feathers, that it might flap to assist stability on high of the prey, together with the stiff tail
- Research of the fowl seriemas (predatory, territorial birds, with lengthy legs and reddish beaks which can be small, weighing as much as nearly 5 lb or a little bit over 2 kg)
- Have recurved sickle claws that in addition they maintain off the bottom like repeaters
- Use them by pinning down prey after which they tear into the animal with their beaks
- Just like the Raptor Prey Restraint (RPR) speculation that Fowler and others got here up with
- In 2019 Peter Bishop made a 3D mannequin of Deinonychus legs and simulated the way it doubtless labored. Discovered the claws have been most definitely for restraining prey and stabbing prey at shut vary (appear to see this with Velociraptor within the Preventing Dinosaurs, the place the Velociraptor is gripping Protoceratops with its claws). However could possibly be the sickle claw use varies among the many raptors
- A examine in 2024, earlier this 12 months, mixed 3D photographs and pc animation to visualise the actions of Deinonychus
- Used 3D fashions of fossils and information from x-ray movies of shifting joints of contemporary animals
- Studied how they chased prey, swam, climbed, and extra
- In contrast x-ray movies of a contemporary fowl strolling on a treadmill, used these movies to measure ankle and toe joint poses of the fowl (guineafowl and emu)
- Used 3D fashions to simulate motions of the identical joints in pc animation software program, testing thousands and thousands of potential poses and score them on how nicely the fowl’s bone surfaces match collectively
- In contrast the best scoring potential poses with actuality of how the birds stroll, discovered an correct match (good for understanding if will probably be correct in depicting prehistoric animal actions)
- Used this method on the stride and foot strike of Deinonychus
- Reconstructed the way it walked, the way it held its sickle claw off the bottom, the way it kicked to assault prey
- Established a framework for a way joints are configured/articulated
- Discovered Deinonychus tentatively did extra inflexible digit stabbing or pinning with claw, relatively than slash or dig (stabbing additionally supported by Velociraptor discovered within the Preventing Dinosaurs)
- Confirmed it saved second toe claw off the bottom (hyperextended posture throughout locomotion)
- Deinonychus has been discovered near fossils of the ornithopod Tenontosaurus (DoD in ep 376)
- (in over 50 Tenontosaurus websites, 14 even have Deinonychus fossils)
- One Tenontosaurus discovered with chew marks from Deinonychus
- Plenty of artwork and statues present poor Tenontosaurus being attacked
- Tenontosaurus is greater than Deinonychus, and discovering them collectively could imply they hunted in packs
- Or could possibly be they have been scavenging
- Potential Deinonychus went after Tenontosaurus the way in which that crocodiles or Komodo dragons right this moment feed (they have a tendency to hunt alone or they begin to eat a carcass, after which different crocodiles or Komodo dragons present as much as eat the carcass and so they find yourself attacking one another. The most important ones eat first. If the smaller ones get killed within the assault, they get eaten too)
- Some Deinonychus people discovered within the space with Tenontosaurus have been subadults and lacking elements of the physique that will imply they have been eaten by different Deinonychus
- Nevertheless, some crocodilians have been seen looking collectively
- And observe websites of theropods appear to point out proof of looking in packs
- Perhaps a little bit of each?
- Juvenile Deinonychus was totally different from grownup Deinonychus
- A 2015 examine checked out progress levels of Deinonychus (juvenile, subadult, and grownup)
- In comparison with Bambiraptor
- One specimen was between one and two years previous (bone histology, one LAG)
- That one to 2 12 months previous weighed between about 7 to nearly 9 kg (about 15 to twenty lb)
- One specimen about 13 to 14 years previous (grownup)
- Juvenile Deinonychus had shorter, shallower jaws than adults
- Had bigger cranium and limb bones in comparison with the vertebral column than adults
- As a juvenile, could have been capable of flap
- Based mostly on the dimensions of the wrist joint, the lengthy arms and hand bones, the big shoulder bones, appears as a juvenile could have been capable of do some flight like issues (like flap)
- Would give the juvenile raptor a bonus (run quicker)
- Would additionally clarify the subadult of Bambiraptor having actually lengthy arm and hand bones
- Additionally, the juvenile dromaeosaurid is estimated to be mild sufficient that it might have flown (weight restrict for contemporary flying birds is about 18 kg (nearly 40 lb)
- However, Deinonychus would have modified because it grew up, so older Deinonychus wouldn’t be capable to fly/flap
- Later research recognized a Deinonychus egg, the primary dromaeosaurid egg to be described
- Eggshell was discovered near Deinonychus gastralia (stomach ribs), which can imply Deinonychus brooded, to maintain the eggs heat (much like trendy birds, which might additionally imply Deinonychus was endothermic, or warm-blooded)
- The Deinonychus that was doubtless brooding was about 13 or 14 years previous and was completed rising
- A 2018 examine discovered Deinonychus laid blue eggs (in all probability for camouflage)
- Potential different raptors had colourful eggs
- Lived in a swamp-like space or floodplain, possibly much like what it’s like in Louisiana right this moment
- Different dinosaurs that lived across the similar time and place embody nodosaurids like Sauropelta, ornithopods like Tenontosaurus and Zephyrosaurus, sauropods like Sauroposeidon
- Different animals that lived across the similar time and place embody crocodilians and fish
- Featured in Harry Adam Knight’s novel Carnosaur (horror novel revealed in 1984) as nicely the movie adaptation Carnosaur (got here out in 1993, a couple of month earlier than Jurassic Park)
- Additionally in Michael Crichton’s novels Jurassic Park and The Misplaced World and the Jurassic Park films (technically they’re Velociraptors, however they’re primarily based on Deinonychus, although they’re the dimensions of Utahraptor)
Enjoyable Truth:
There’s fossil proof of theropod dinosaurs dancing.
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