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Post by brobear on Apr 3, 2021 7:18:15 GMT -5
Laramidia - Kingdom of T-rex: Less ice at the poles; more water.
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Post by brobear on Apr 5, 2021 5:45:53 GMT -5
From FaceBook group: Tyrannosauroidea and: www.skeletaldrawing.com/home/mass-estimates-north-vs-south-redux772013 Was T.rex the heaviest theropod known to science? William Wisson-Burton Estimates put a fully grown adult between 7 and 11 tonnes. Giganotosaurus has been evaluated at 6 to 8 tonnes. So, while there is a tiny bit of overlap between their weight ranges, T rex is undoubtedly heavier. Luigi Gaskell The heaviest *so far that we have a reliable sample size from that can be measured and estimated with some degree of confidence* Alessandro Zotti It currently holds the title, which doesn't come as a surprise seeing how thic-ehm, robust it was, but also because of the wider sample size (litterally!) compared to other giant theropods. Calin Erbe Heaviest so far yeah. It currently outweighs Giganotosaurus by at least 1-2 tons. Then again, we don't have many specimens for the Giga. The tyrant of South America was at the very least close to rex in size. At the same time, even though we have dozens of Tyrannosaurus specimens, it's not entirely certain what the maximum size for the animal may be. Scotty may have been just average in weight for his old age or a bit on the thicker side. Who really knows. Malcolm Daniel Tyrannosaurus rex has been found to be heavier than Giganotosaurus, and long before Scotty’s mass was calculated. Spinosaurus’ mass is still largely a mystery, but the most recent estimates place it at around seven tons. Longest doesn’t mean heaviest as well; just ask the reticulated python and the green anaconda.
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Post by brobear on Apr 6, 2021 1:29:02 GMT -5
Tyrannosaurus rex (sue) with Loxodonta africanus by frannoys
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Post by brobear on Apr 6, 2021 8:24:06 GMT -5
www.sciencedaily.com/releases/2021/03/210309114354.htm Younger Tyrannosaurus Rex bites were less ferocious than their adult counterparts. By closely examining the jaw mechanics of juvenile and adult tyrannosaurids, some of the fiercest dinosaurs to inhabit earth, scientists have uncovered differences in how they bit into their prey. By closely examining the jaw mechanics of juvenile and adult tyrannosaurids, some of the fiercest dinosaurs to inhabit earth, scientists led by the University of Bristol have uncovered differences in how they bit into their prey. They found that younger tyrannosaurs were incapable of delivering the bone-crunching bite that is often synonymous with the Tyrannosaurus rex and that adult specimens were far better equipped for tearing out chunks of flesh and bone with their massive, deeply set jaws. The team also found that tension from the insertion of the lower pterygoid muscle is linked to decreasing stresses near the front of the typical tyrannosaur jaw, where the animals may have applied their highest impact bite forces using their large, conical teeth. This would be advantageous with the highly robust teeth on the anterior end of the tyrannosaur jaw, where, usually, they may have applied their highest impact bite forces. Crocodilians experience the reverse situation -- they possess robust teeth near the posterior end of their mandible where they apply their highest bite forces. Adult tyrannosaurids have been extensively studied due to the availability of relatively complete specimens that have been CT scanned. The availability of this material has allowed for studies of their feeding mechanics. The adult Tyrannosaurus rex was capable of a 60,000 Newton bite (for comparison, an adult lion averages 1,300 Newtons) and there is evidence of it having actively preyed on large, herbivorous dinosaurs. The team were interested in inferring more about the feeding mechanics and implications for juvenile tyrannosaurs. Their main hypotheses were that larger tyrannosaurid mandibles experienced absolutely lower peak stress, because they became more robust (deeper and wider relative to length) as they grew, and that at equalized mandible lengths, younger tyrannosaurids experienced greater stress and strain relative to the adults, suggesting relatively lower bite forces consistent with proportionally slender jaws. At actual size the juveniles experienced lower absolute stresses when compared to the adult, contradicting our first hypothesis. This means that in real life, adult tyrannosaurs would experience high absolute stresses during feeding but shrug it off due to its immense size. However, when mandible lengths are equalized, the juvenile specimens experienced greater stresses, due to the relatively lower bite forces typical in slender jaws. Lead author Andre Rowe, a Geology PhD Student at the University of Bristol's School of Earth Sciences, said: "Tyrannosaurids were active predators and their prey likely varied based on their developmental stage. "Based on biomechanical data, we presume that they pursued smaller prey and fulfilled an environmental role similar to the 'raptor' dinosaurs such as the dromaeosaurs. Adult tyrannosaurs were likely subduing large dinosaurs such as the duckbilled hadrosaurs and Triceratops, which would be quickly killed by their bone-crunching bite. "This study illustrates the importance of 3D modeling and computational studies in vertebrate paleontology -- the methodology we used in our study can be applied to many different groups of extinct animals so that we can better understand how they adapted to their respective environments." There are two major components of this research that Andre and the team would like to see future researchers delve into continued CT and surface scanning of dinosaur cranial material and more application of 3D models in dinosaur biomechanics research. Andre added: "There remains a plethora of unearthed dinosaur material that has not been utilized in studies of feeding and function -- ideally, all of our existing specimens will one day be scanned and made widely available online to researchers everywhere. "The current lack of 3D model availability is noticeable in dinosaur research; relatively few studies involving 3D models of carnivorous dinosaurs have been published thus far. There is still much work to be done concerning skull function in all extinct animals -- not only dinosaurs."
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Post by tom on Apr 6, 2021 11:51:01 GMT -5
Way back when I in grammar school I remember studying the Dinosaurs and remember one such species called "Allosaurus" which is in the same class "Neotheropod apex carnivores" as T-Rex and Ceratosaurs. He did not live in the same time period as T-REX and lived much earlier in the late Jurassic period (150 million years ago) while T-REX in the Cretaceous period some 65 million years ago. T-REX was considerably heavier and bulkier than Allosaurus. www.britannica.com/animal/AllosaurusAllosaurus weighed two tons and grew to 10.5 metres (35 feet) in length, although fossils indicate that some individuals could have reached 12 metres. Half the body length consisted of a well-developed tail, and Allosaurus, like all theropod dinosaurs, was a biped. It had very strong hind limbs and a massive pelvis with strongly forward- (anteriorly) and rearward- (posteriorly) directed projections. The forelimbs were considerably smaller than the hind limbs but not as small as those of tyrannosaurs. The forelimbs had three fingers ending in sharp claws and were probably used for grasping.
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Post by tom on Apr 6, 2021 11:52:26 GMT -5
While Allosaurus was a formidable predator and preyed upon larger herbivores, he likely would have been no match for a T-REX had they lived in the same time period and location.
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Post by brobear on Apr 6, 2021 17:49:37 GMT -5
Allosaurus was a favorite back when I was in elementary school too. Back then, in school, I was the "dinosaur guy" who read books and knew "all about dinosaurs". As a kid, I had hundreds of colorful plastic animals and most were dinosaurs. Pictured: cheap Chinese copies of what I had as a kid. Bottom far right is 1950s version of Allosaurus.
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Post by brobear on Apr 7, 2021 1:01:50 GMT -5
FaceBook group - TYRANNOSAURUS REX Ceratopsians weren't the only ones involved in an arm race against tyrannosaurs, hadrosaurs were involved in a similar race too. Comparison between Edmontosaurus and Tyrannosaurus.
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Post by brobear on Apr 7, 2021 1:21:34 GMT -5
FaceBook group - Tyrannosauroidea Tyrannosaurus rex and relatives Paleoart by Zhao Chuang
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Post by brobear on Apr 8, 2021 9:28:10 GMT -5
My Take ( simply opinion ) 1- T-rex vs Spinosaurus = T-rex 10 out of 10. 2- T-rex vs Giganotosaurus = T-rex 8 out of 10. 3- T-rex vs Carcharodontosaurus = T-rex 8 out of 10. Q- could i be wrong? A- Easily. Its a matter of bulk vs agility and bone-crushing teeth vs meat-slicing teeth.
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Post by brobear on Apr 9, 2021 12:48:35 GMT -5
See map ( reply #21 )- www.theblaze.com/news/biden-tax-hikes-would-cost-1-million-jobs?utm_source=theblaze-breaking&utm_medium=email&utm_campaign=20210409Trending-BidenTaxHikes&utm_term=ACTIVE%20LIST%20-%20TheBlaze%20Breaking%20News Tyrannosaurs In Late Cretaceous North America, the dominant predators were the tyrannosaurs, huge predatory theropods with proportionately massive heads built for ripping flesh from their prey. Tyrannosaurs were the dominant predators in Appalachia too, but rather than the massive Tyrannosauridae, like Gorgosaurus, Albertosaurus and Lythronax, which evolved around the same time that the Western Interior Seaway had fully separated Laramida from Appalachia, the smaller dryptosaurs were the top predators of Appalachia. Rather than developing the huge heads and massive bodies of their kin, dryptosaurs had more in common with the basal tyrannosaurs like Dilong and Eotyrannus, having long arms with three fingers, and were not as large as the largest tyrannosaurids, though fossils from the Potomac Formation in New Jersey show that some of them did evolve some of the large-bodied features that can be found on other tyrannosaurs. Three genera of valid Appalachian tyrannosaurs are known, Dryptosaurus, Appalachiosaurus, and the recently discovered Teihivenator while other indeterminate fossils lie scattered throughout most of the southern United States like Georgia, North Carolina, and South Carolina. Fossil foot bones from Appalachian deposits indicate another, unnamed tyrannosauroid measuring 9 m (30 ft), indicating that diversity in these basal tyrannosauroids remained high during the latest cretaceous. These fossilized teeth possibly belong to a species of Appalachiosaurus or an undescribed species of a new tyrannosaur.[31][32] There is also the possibility of a fourth tyrannosaur known from Applachia known as Diplotomodon, but this is highly unlikely seeing how the genus is considered to be dubious. Fossils from New Jersey and Delaware, most notably in the Mt. Laurel Formation and Merchantville Formation respectively, have revealed that the primitive tyrannosauroids were much more diverse than expected, and some of them grew to lengths of 8 to 9 meters long, making them around the same size as some of the more advanced tyrannosaurs found in Laramidia. Fossils in Cenomanian deposits further indicate tyrannosauroids had been a constant presence in Appalachia since the middle cretaceous. ( see also Appalachiosaurus ). Dryptosaurus - en.wikipedia.org/wiki/Dryptosaurus dinopedia.fandom.com/wiki/Dryptosaurus
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Post by brobear on Apr 12, 2021 23:09:29 GMT -5
( one possible outcome )
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Post by brobear on Apr 15, 2021 5:02:04 GMT -5
Tyrannosaurus Rex - The Tyrant King - edited by Peter Larson and Kenneth Carpenter. Condensed: heterochronic trade-offs ( evo-devo ) Such developmental exaggerations or emphasis in one organ or region of the body inevitably results in underdevelopment in adjacent organs, as required by the principle of compensation. *To simplify, T-rex traded off his arms and claws for a huge head with powerful jaws armed with bone-crushing teeth.
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Post by brobear on Apr 15, 2021 7:04:16 GMT -5
Tyrannosauroidea - en.wikipedia.org/wiki/TyrannosauroideaPhylogeography In 2018 authors Rafael Delcourt and Orlando Nelson Grillo published a phylogenetic analysis of Tyrannosauroidea which incorporated taxa from the ancient continent of Gondwana (which today consists of the southern hemisphere), such as Santanaraptor and Timimus, whose placement in the group has been controversial. They have found that not only Santanaraptor and Timimus were placed as tyrannosaurs more derived than Dilong, but they have found in their analysis that tyrannosauroids were widespread in Laurasia and Gondwana since the Middle Jurassic. They have proposed new subclade names for Tyrannosaurioidea. The first is Pantyrannosauria referring to all non-proceratosaurid members of the group, while Eutyrannosauria for larger tyrannosaur taxa found in the northern hemisphere such as Dryptosaurus, Appalachiosaurus, Bistahieversor, and Tyrannosauridae. Below is their phylogeographic tree they have recovered, in which displays the phylogenetic relationships of the taxa as well as the continents those taxa have been found. T-rex was the largest member of a large family of Coelurosauria.
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Post by brobear on Apr 15, 2021 23:55:32 GMT -5
www.businessinsider.com/total-t-rex-population-study-2021-4?utm_medium=social&utm_campaign=sf-bi-main&utm_source=facebook.com&fbclid=IwAR0vqOrwFfPpgxJGJVSe0Sgcd6aoEIDvIU4SsT4MGqYDAIY-3DnTlH8_gEo A whopping 2.5 billion fully grown T. rexes walked the Earth in the course of the species' existence, paleontologists found. The Tyrannosaurus rex was around for 2.5 million years before the dinosaurs went extinct. A new study suggests that a total of 2.5 billion adult T. rexes lived and died during that period. Paleontologists arrived at the figure by calculating the T. rex life span and population density. See more stories on Insider's business page. www.sciencealert.com/scientists-estimated-how-many-t-rex-s-existed-in-all-of-history-and-here-s-what-they-came-up-with?fbclid=IwAR1YnF8Op1nSIRYSbfJugDFo4DiVBwDnsgTu3Me2q5KD5EJDt9OXIn8viXA There Were a Whole Lot More T. Rex Terrorizing Earth Than You Might Imagine. For two and a half million years, the most infamous of predators, Tyrannosaurus rex, slowly stomped its way around what is today North America's western coast. Scientists have now come up with an estimate for the total number of T. rex that ever existed: around 2.5 billion (yes, billion). This may sound like a lot - and it's certainly more than you picture when watching them stalking around solo in films such as Jurassic Park. But to put it into perspective, by some calculations it's estimated that more than 100 billion 'modern' Homo sapiens have called Earth home at some point, and that number is still getting bigger by the year. While knowing how many individuals once lived of any particular long dead species may not mean much in and of itself, this type of exercise can provide researchers with some insight into past ecologies and species completely missing from the fossil record. A team of researchers led by University of California paleontologist Charles Marshall, chose T. rex as their subject because these giant beasties are the most well understood dinosaur. They used Damuth's Law, an ecological equation that describes the relationship between body size and population density, which was derived by studying living species. In rough terms, the larger the individual animal, the lower its population density, with some weighting also given to trophic level (where they lie on the food chain) and their physiology. "Establishing [T. rex's] physiology has proven challenging," the team wrote in their paper. This measure is important because among living species those with slower metabolisms can sustain larger population densities. Whether dinosaurs were warm or cold blooded is a hotly debated topic, so reviewing the scientific literature the team decided to assume a physiology somewhere in between - midway between a large mammalian carnivore and that of a large land lizard like a Komodo dragon. Using the fossil record the team obtained a mean weight of 5,200 kilograms (11,500 pounds) for the species. After all the number crunching the researchers arrived at the estimate of 20,000 individual T. rex living at any given time during their existence. Based on estimates involving their growth rates and sizes, the team also determined their population density, a figure that roughly equated to 3,800 of these fearsome predators stalking an area equal to California. Previous estimates on dinosaur abundance based on fossil finds at Hell Creek Formation suggested an abundance level greater than expected from a typical predator, suggesting among other things that T. rex adults did not compete with their juveniles for the same food sources. This has since been backed up by more research. And while T. rex appears to have been quite common in this location (this is where most of their fossils have been found), Triceratops were the most common species represented in the fossil record, so it would be interesting to see estimates of their total abundance in comparison. Given how many assumptions have been made to obtain these abundance estimates, they of course have high uncertainty levels. "Nonetheless, our capacity for inferring population sizes of extinct taxa greatly exceeds what [was] thought possible more than 75 years ago," Marshall and colleagues wrote. "This capacity has been enabled by the discovery of many more fossils and the ability to establish growth and survivorship curves from age and body mass estimates." These estimates suggest only one per 80 million of them have been recovered as fossils - highlighting just how precious and rare such remains really are. Marshall and colleagues hope this technique can hint at how rare, short lived or restricted a species is likely to have been to have escaped being fossilized for our discovery. This research was published in Science.
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Post by OldGreenGrolar on Apr 16, 2021 0:53:09 GMT -5
Imagine an earth where T. rex still rule. They would be bigger than most of our vehicles today.
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Post by brobear on Apr 16, 2021 0:55:14 GMT -5
www.smithsonianmag.com/science-nature/the-tyrannosaurus-rexs-dangerous-and-deadly-bite-37252918/ The Tyrannosaurus Rex’s Dangerous and Deadly Bite. The dinosaur had the strongest bite of any land animal – even harder than we previously thought. Tyrannosaurus rex has always been recognized as fearsome—the New York Times labeled it the “prize fighter of antiquity” when the first mounted T. rex bones were displayed in 1906—but thanks to two British researchers, it’s now clear that the giant carnivore bit harder than experts had thought. A lot harder. Karl Bates, a biomechanics expert at the University of Liverpool, and Peter Falkingham, a paleontologist at the Royal Veterinary College, London, and Brown University, acknowledge that measuring the biomechanics of an extinct species “is notoriously difficult and involves numerous assumptions.” But for their assessment of T. rex’s bite, published in Biology Letters, they constructed a three-dimensional digital model of the animal’s skull and reconstructed the relevant jaw musculature, based on anatomical research on birds (which are, after all, living dinosaurs) and crocodilians (the closest living cousins to Dinosauria as a group). Previous assessments relied on extrapolations from crocodile bites or fossil T. rex tooth marks. When Bates and Falkingham used computer models to simulate T. rex’s bite, the result was “quite surprising,” Bates told us: a maximum bite force of almost 12,800 pounds, about the equivalent of an adult T. rex’s body weight (or 13 Steinway Model D concert grand pianos) slamming down on its prey. That would make T. rex the hardest-biting terrestrial animal ever known. (C. megalodon, an extinct giant shark, bit at an estimated 41,000 pounds; Deinosuchus, an ancient crocodilian, at about 23,000 pounds.) Bates and Falkingham’s figure was two to three times greater than previous estimates, six to seven times greater than the biting force they calculated for the dinosaur Allosaurus and about three and a half times greater than the hardest bite measured in an extant species, an Australian saltwater crocodile. “The posterior part of the skull that housed the muscles was particularly large,” Bates says. Rare juvenile T. rex skeletons indicate that these dinosaurs were leggy runners with relatively shallow skulls incapable of anchoring muscles that would generate a bite proportional to the adults’. In Bates and Falkingham’s tests, juvenile T. rex bites topped out at about 880 pounds. But as the animal matured, its jaw-closing muscles grew exponentially, to the point where they were huge “even for an animal of its colossal size.” Young T. rex were still formidable—they just targeted different prey. While the juveniles raced down small game, Bates notes, the adults had the power to bring down megaherbivores such as Edmontosaurus and Triceratops. This phenomenon, called resource partitioning, would have reduced competition between parents and offspring—a big evolutionary advantage. As if T. rex needed it.
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Post by brobear on Apr 16, 2021 1:00:46 GMT -5
Reply #38 - So, even though T-rex had the most powerful bite force of any land-based animal ever, Deinosuchus, the giant ( aquatic ) crocodile who "lived in the same woods", had a bite force even greater. My thoughts, these two monsters were probably each other's greatest challenge.
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Post by OldGreenGrolar on Apr 16, 2021 1:00:58 GMT -5
The triceratops is one of the deadliest prey item of the T. rex.
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Post by brobear on Apr 16, 2021 1:03:03 GMT -5
The triceratops is one of the deadliest prey item of the T. rex. This is true; even though also a favorite prey choice.
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