Episode 500: Raptor Renaissance!. This historical past of dromaeosaurs (higher often known as 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 hen 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 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 Crimson 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
- 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
- Enamel that will belong to Deinonychus have additionally been present in Maryland (Potomac Formation)
- Seemed just 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 giant arms with three claws
- Most likely coated in feathers, primarily based on it wanting like a hen and being intently associated to different raptors (the place feathers have been discovered, corresponding to Microraptor and Velociraptor—quill knobs discovered on the arm of Velociraptor)
- No direct proof of getting feathers, but
- Had giant sickle-clawed second toe (for reducing or slashing, not designed for greedy or digging)
- Second toe was “tailored completely for predation”
- Different toes round it helped with standing and shifting
- Sort and solely species is Deinonychus antirrhopus
- Genus title means “horrible claw”
- Genus title refers back to the giant, sickle-shaped claws on its second toes
- Species title antirrhopus means “counter steadiness” and refers back to the stiff tail that will have helped it
- Nonetheless, one specimen of Velociraptor discovered later had a tail that curved and should have been capable of bend to the perimeters
- Fossils first present in 1931 close to Billings, Montana
- Barnum Brown was main a crew
- Principally targeted on Tenontosaurus on the time however talked about the Deinonychus fossils had been “encased in lime tough 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 at the least three people
- Arduous to know which bones belonged to which particular person, so laborious to know precisely what number of people
- Sort 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)
- Sort specimen had a strongly curved sickle claw
- Different specimens weren’t as strongly curved
- Might be from particular person variation
- Additionally discovered vertebrae, almost full arms, components of the cranium, foot bones, components of the shoulder, components 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’s only by likelihood” they’re included within the research
- 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 shall 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 not like any beforehand reported dinosaur”
- Ostrom printed a pair monographs on Deinonychus
- Extra fossils present in 1974 to assist fill in a few of the gaps (together with within the hip and pubis space)
- Had extra of a hen hip (backwards going through)
- Ostrom’s description of Deinonychus result in the Dinosaur Renaissance (Nineteen Sixties to Nineteen Eighties-ish the place scientists began seeing dinosaurs as extra lively and agile once more, as a substitute of gradual, lumbering reptiles)
- In 1969, Ostrom wrote that Deinonychus was proof that dinosaurs had been lively (all primarily based on the foot)
- “For my part, the foot of Deinonychus is probably essentially the most revealing little bit of anatomical proof pertaining to dinosaurian habits and capabilities to be found in lots of a long time. Grandiose statements of this type are, after all, simply rejected, however the practical implications of the pes of Deinonychus should not so simply discarded—particularly in view of the opposite outstanding diversifications of this animal. Deinonychus should have been something however “reptilian” in its conduct, responses and lifestyle. It should have been a fleet-footed, extremely predaceous, extraordinarily agile and really lively animal, delicate to many stimuli and fast in its responses. These in flip point out an uncommon degree of exercise for a reptile and counsel an unusually excessive metabolic charge. The proof for these lie mainly, however not completely, within the pes.”
- Ostrom additionally wrote:
- “It needs to be fairly apparent that this machine couldn’t be used except the animal stood on one leg. It’s also apparent that the usage of this construction necessitated important agility and maybe even violent exercise whereas standing on that one limb.”
- Deinonychus was an lively meat eater
- Ostrom in 1969 stated it was a “flesh-eater and nearly definitely a predator”
- Sharp enamel, lengthy arms with claws on the arms, stiff tails, and sickle-like claws on the second toes all would have helped
- A research earlier this 12 months, in 2024 by Tse, Miller, and Pittman discovered Deinonychus had a narrower cranium, had comparatively excessive chunk pressure/comparatively sturdy chunk in comparison with different raptors
- Had a tall, brief cranium
- Gradual, sturdy bites
- However, excessive pressure on the cranium
- May go after giant prey, however cranium is comparatively much less proof against chunk forces than different dromaeosaurids
- Might be it used its neck muscle tissue to tug again on prey, or possibly had a large gape (might open its mouth huge)
- Possibly 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 arms 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 alternative foot)
- Ostriches and cassowaries may cause critical harm with the massive claws on their internal 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 internal toes”
- One other paper in 1962 by Austin stated the “ostrich prefers to run, however when compelled to combat 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
- Newer research discovered the claws had 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 ultimately it dies from shedding blood and organ failure)
- Referred to as the Raptor Prey Restraint (RPR) speculation
- Based mostly on evaluating the toes and legs of dromaeosaurs to trendy birds of prey (just like eagles and hawks, based on Denver Fowler and others)
- Nonetheless, foot power from its shorter toes (had brief metatarsus or higher foot bones) could be extra just like owls
- Arms could have been coated in lengthy feathers, that it might flap to assist steadiness on prime of the prey, together with the stiff tail
- Research of the hen seriemas (predatory, territorial birds, with lengthy legs and reddish beaks which might be small, weighing as much as nearly 5 lb or somewhat over 2 kg)
- Have recurved sickle claws that additionally 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 had been most probably for restraining prey and stabbing prey at shut vary (appear to see this with Velociraptor within the Combating Dinosaurs, the place the Velociraptor is gripping Protoceratops with its claws). However might be the sickle claw use varies among the many raptors
- A research in 2024, earlier this 12 months, mixed 3D photographs and laptop animation to visualise the actions of Deinonychus
- Used 3D fashions of fossils and information from x-ray movies of shifting joints of recent animals
- Studied how they chased prey, swam, climbed, and extra
- In contrast x-ray movies of a contemporary hen strolling on a treadmill, used these movies to measure ankle and toe joint poses of the hen (guineafowl and emu)
- Used 3D fashions to simulate motions of the identical joints in laptop animation software program, testing hundreds of thousands of potential poses and score them on how effectively the hen’s bone surfaces match collectively
- In contrast the very best scoring potential poses with actuality of how the birds stroll, discovered an correct match (good for figuring out if it is going to be correct in depicting prehistoric animal actions)
- Used this strategy 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, fairly than slash or dig (stabbing additionally supported by Velociraptor discovered within the Combating 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
- A number 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 might be they had been scavenging
- Doable 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 biggest 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 had been subadults and lacking components of the physique that will imply they had been eaten by different Deinonychus
- Nonetheless, some crocodilians have been seen looking collectively
- And observe websites of theropods appear to point out proof of looking in packs
- Possibly a little bit of each?
- Juvenile Deinonychus was completely different from grownup Deinonychus
- A 2015 research checked out development levels of Deinonychus (juvenile, subadult, and grownup)
- In comparison with Bambiraptor
- One specimen was between one and two years outdated (bone histology, one LAG)
- That one to 2 12 months outdated weighed between about 7 to nearly 9 kg (about 15 to twenty lb)
- One specimen about 13 to 14 years outdated (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 scale of the wrist joint, the lengthy arms and hand bones, the massive 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 sooner)
- 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 of 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 (just 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 outdated and was performed rising
- A 2018 research discovered Deinonychus laid blue eggs (in all probability for camouflage)
- Doable different raptors had colourful eggs
- Lived in a swamp-like space or floodplain, possibly just like what it’s like in Louisiana right this moment
- Different dinosaurs that lived across the identical time and place embrace nodosaurids like Sauropelta, ornithopods like Tenontosaurus and Zephyrosaurus, sauropods like Sauroposeidon
- Different animals that lived across the identical time and place embrace crocodilians and fish
- Featured in Harry Adam Knight’s novel Carnosaur (horror novel printed in 1984) as effectively the movie adaptation Carnosaur (got here out in 1993, a few 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 scale of Utahraptor)
Enjoyable Reality:
There may be fossil proof of theropod dinosaurs dancing.
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