Episode 85 is all about Carnotaurus, a big theropod with thick horns above its eyes.
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On this episode, we talk about:
- The dinosaur of the day: Carnotaurus
- Identify means “meat consuming bull” as a consequence of it’s bull-like horns
- Giant theropod that lived within the Late Cretaceous, in what’s now South America
- Kind species is Carnotaurus sastrei
- Species title is in honor of Angel Sastre, the proprietor of the ranch had been the skeleton was discovered (skeleton discovered on ranch named “Pocho Sastre”)
- Skeleton was present in 1984
- Jose Bonaparte discovered Carnotaurus in 1984, as a part of one of many expeditions within the undertaking “Jurassic and Cretaceous Terrestrial Vertebrates of South America” (sponsored by the Nationwide Geographic Society that began in 1976)
- Skeleton was of an grownup, and cranium and muzzle had been crushed in fossilization
- It took a very long time to arrange the skeleton, because it was in very arduous rock (hematite); Jose Bonaparte wrote a word naming Carnotaurus in 1985 describing the cranium and a extra full description was written in 1990
- A part of Abelisauridae (group of huge theropods)
- Closest kin are in all probability both Aucasaurus or Majungasaurus
- Different animals discovered close to Carnotaurus embrace turtiels, snakes, crocodiles, mammals
- Bipedal, about 26-30 ft (8-9m) lengthy and weighing about 1.3-2.1 tons
- Small forelimbs and lengthy, slender hindlimbs
- Forelimbs had been proportionally shorter than different carnivores, even T-rex (forearm was 1/4 the scale of the higher arm)
- Hand had 4 digits, however solely the 2 center ones had finger bones; the fingers had been fused, motionless and doubtless didn’t have claws; the 4th digit was a split-like metacarpal that will have been some form of spur
- A research in 2009 discovered that abelisaurids had vestigal arms (had decreased nerve fibers like in trendy emus and kiwis, which have vestigial forelimbs)
- If Carnotaurus stored evolving, descendants could have misplaced its arms
- Had thick horns above its eyes (not seen on different carnivores)
- Very specialised (horns and neck)
- Had a deep cranium and muscular neck
- Had a straight neck, as a substitute of an s-curved neck like different theropods, and was broad in direction of the bottom
- Potential it used its head like a hatchet (together with thick, lengthy neck) and enamel struck the prey a number of occasions to take it down
- Might have fought utilizing horns and neck and both pushing their skulls collectively, or ramming heads and utilizing horns as shock absorbers
- Bone horns on the forehead had been 5.9 in (15 cm) lengthy (in all probability keratin made them longer)
- Horns could have been used for combating, show, or killing prey
- Horns could have protected eyes in fights, or been utilized in fights the best way rams use horns (in 1998 Gerardo Mazzetta and crew discovered that Carnotaurus‘ neck was robust sufficient to soak up the pressure of two Carnotaurus‘ butting heads at a velocity of 5.7 m/s every
- Gerardo Mazzetta additionally stated the horns might have damage or killed small prey
- Some research discovered that as a substitute of head blows Carnotaurus‘ pushed slowly towards one another with their skulls, so the horns might assist stop mind harm (horns had been flat on the higher facet and high of the cranium had strongly fused bones)
- In 2009 Fernando Novas stated the brief cranium could have helped them transfer their heads extra shortly, and the robust neck and rigidity and power of their spinal columns might assist when butting heads
- Cranium is 23.5 in (59.6 cm) lengthy and proportionately brief and deep
- Broad snout, and nasal bones had small holes and spikes
- Had small eyes and some extent of binocular imaginative and prescient
- Eyes set going through barely forwards
- Might have been in a position to hunt sauropods, although some scientists assume it ate small animals
- Might chew shortly, however didn’t have a powerful chew (additionally good for small prey)
- Lengthy, slender enamel, with a shallow, weak decrease jaw
- Cranium and decrease jaw was versatile, like trendy snakes, so might swallow small animals entire, and enamel pointed upwards to maintain the animal from escaping its jaws.
- However could have additionally been in a position to hunt massive dinosaurs, for the reason that cranium might face up to the pressure of biting bigger prey
- In 2005, Francois Therrien and colleagues discovered that Carnotaurus had a chew pressure 2x a contemporary American alligator and was just like Komodo dragons, which have jaws which can be higher for slashing and weakening massive prey, so Carnotaurus could have ambushed and killed massive animals
- Robert Bakker stated in 1998 that Carnotaurus in all probability ate sauropods, because it’s brief snout and small enamel and powerful again of the cranium had additionally advanced, independently, in Allosaurus
- Good runner
- Might dash, although in all probability not fairly as quick as ornithomimids
- Individual and Currie printed a research in 2011, the place they studied 50 species of carnivorous dinosaurs, all completely different sizes, and located that Carnotaurus was the ninth quickest dinosaur, due to its muscle tissue within the tail
- Unclear precisely how briskly Carnotaurus might have run
- Carnotaurus was in all probability quick, as a result of it had caudal ribs in a “V” form within the tail vertebrae, which meant it had room to have a bigger caudofemoralis muscle than different theropods (most vital muscle for locomotion and should have weighed as much as about 300 kilos or 140 kg). Nevertheless, different muscle tissue that assist with tail motion and stability (longissimus and spinalis muscle) had been smaller, which meant it could have had a tough time making tight turns as a result of the hip and tail needed to flip on the identical time, not like different theropods
- Caudofemoralis is a pair of huge muscle tissue on the perimeters of the tails
- Tail had two caudal ribs (crescent-shaped flanges on the perimeters of the tail bones); all about 15% of its physique weight
- Carnotsaurus fossils had pores and skin impressions that confirmed a mosaic of polygonal, small scales (5mm in diameter) with massive bumps on the perimeters of Carnotaurus, however in all probability no feathers
- Pores and skin impressions discovered on the decrease jaw, entrance of the neck, shoulder, and rib cage, and tail. There have been patches of pores and skin impressions on the correct facet of the cranium too, however it wasn’t clear what they had been when the cranium was ready, so that they had been by chance destroyed (although scientists nonetheless discovered that the sample on the left and proper sides of the cranium was completely different)
- Head had a distinct sample in comparison with the physique
- Had massive, knob-like bumps on the facet of the neck, again, and tail, in irregular rows
- Bumps had been bigger in direction of the highest of Carnotaurus (in all probability had been clusters of scutes, as seen on hadrosaurids); could have helped shield its sides when combating both different Carnotaurus‘ or different theropods (just like what iguanas have, which helps shield them in fights)
- No proof of feathers
- Holotype is on show on the Argentine Museum of Pure Sciences
- Can see a life-sized sculpture on the Pure Historical past Museum in LA (made by Stephen and Sylvia Czerkas, museum ordered it within the mid-Eighties, and is without doubt one of the first theropod replicas to indicate pores and skin precisely
- In The Misplaced World by Michael Crichton, there are Carnotaurus‘ that may camouflage, and the characters scare them away with flashlights
- Abelisauridae means “Abel’s lizards”
- Clade of ceratosaurian theropods that lived within the Jurassic and Cretaceous in Gondwana (Africa, South America, India, and Madagascar)
- Jose Bonaparte and Fernando Novas named Abelisauridae in 1985, after they described Abelisaurus (named after Roberto Abel, who found Abelisaurus)
- Bipedal and carnivorous
- Had brief hindlimbs and ornamentation on the cranium bones
- Skulls had been usually tall and shallow
- 4 digits on the hand
- Abelsaurids are additionally a part of the group ceratosaurs (Limusaurus and Ceratosaurus ahd brief arms within the Jurassic, like abelisaurids)
- Enjoyable truth: Virtually 200 birds have been pushed to extinction for the reason that yr 1500. Some had been pushed to extinction by people searching just like the dodo, moa, & elephant chicken. However much more have gone extinct as a consequence of species launched by people. In response to Birdlife.org: “Within the final 500 years, species like rats, cats and mice have pushed greater than 70 chicken species to extinction. They continue to be one of many biggest threats to our pure world.”Subsequently after the Chicxulub impactor the best risk to dinosaurs might be people and our introduction of invasive species to new habitats.
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