Dinosaurs would have continued to thrive - But Meteor Came
Nov 19, 2020 21:15:39 GMT
shannondegroot likes this
Post by dividavi on Nov 19, 2020 21:15:39 GMT
I take strong exception to this CNN article and the claims from the University of Bath.
Why do researchers completely ignore the possibility that mammals
may have been a factor in the extinction of the dinosaurs some 65 mya?
Instead, they say that mammals and dinosaurs co-existed throughout the
Jurassic and Cretaceous and that this demonstrates that mammals did not
consume the Dinosaur young leading to the demise of that group. I remember
this theory from a 1950's textbook.
Giant reptiles (turtles) have "ruled" the Galapagos islands for a long
time. It is my understanding that recently imported dogs and cats have
caused a decline in the turtle population due to their predation of turtle
hatchlings. The same predation has also reduced the population of the other
Galapagos "rulers", the Iguanas. Why is it not a feasible possibility that
newly evolved (Late Cretaceous that is) placental mammals damaged the
dinosaur population by eating their young. The adult Dinosaurs (just like
adult Galapagos turtles) would be invulnerable to mammal attack but their
young would not be so lucky. Question--- When did definable placental
mammals evolve? Was it not in the Late Cretaceous, at about the same time
that the number of Dinosaur species declined?
Newly imported mammal species also exterminated the "rulers" of Mauritius,
the Dodos, some 3 centuries ago and seem to be doing the same today to the
ruling Tuataras, Kiwis and Parrots of New Zealand. In addition, it is my
understanding that the largest predator of the Paleocene (post Dinosaur)
was the 2 metre tall Diatryma which was eventually superseded by mammalian
Creodonts and true carnivores. Is my understanding correct? If Diatryma was
destroyed by placental mammal competition why not Troodonts or Velociraptors.
I do not claim that mammals were the sole or even a major cause of Dinosaur
extinction. I believe that it was a factor and should not be summarily dismissed.
Dinosaurs would have continued to thrive had it not been for the asteroid, researchers say
edition.cnn.com/2020/11/18/world/dinosaur-extinction-intl-scli-gbr-scn/index.html
By Amy Woodyatt, CNN
Updated 1555 GMT (2355 HKT) November 18, 2020
(CNN)Dinosaurs were doing well and could have continued to dominate Planet Earth if they had not been wiped out by an asteroid, new research has found.
After emerging during the Triassic period some 230 million years ago, dinosaurs occupied every continent and were dominant in most terrestrial ecosystems, until they were rendered extinct by the asteroid impact 66 million years ago.
Some scientists believe the creatures were beginning to lose their edge and were already heading for extinction when the asteroid hit Earth at the end of the late Cretaceous period.
But researchers from the UK's University of Bath are hoping to put this theory to bed. Gathering diverse and up-to-date data, researchers used statistical analysis to assess whether the dinosaurs were still able to produce new species up until their untimely demise.
An artist's interpretation of the asteroid impact that wiped out all non-avian dinosaurs
"What we found is that the dinosaurs were still dominant, they were still widespread and still doing really well," Joe Bonsor, first author of the study, said in a statement.
"If the asteroid impact had never happened then they might not have died out and they would have continued after the Cretaceous," Bonsor, a PhD student at London's Natural History Museum and the Milner Centre for Evolution at the University of Bath, added.
During their more than 150 million years on earth, dinosaurs evolved to take many shapes and forms -- some dinosaurs were tiny, while others measured over 100 feet. Experts think diversity was the key to their dominance on Earth, with some boasting armors, crests, teeth and even feathers.
Previous research had suggested that this diversity was starting to decline, and that dinosaurs were beginning to lose their dominance.
But the study published Tuesday in the journal The Royal Society Open Science argues that the earlier research reached this conclusion by modeling dinosaur family trees based on previous fossil records.
The University of Bath researchers say that, after looking at a greater number of dinosaur groups, their more up-to-date and detailed family trees show that dinosaurs on every continent were in fact flourishing, with plant-eating animals such as hadrosaurs, ceratopsians and ankylosaurs dominant in North America, and carnivorous abelisaurs continuing to thrive in South America.
"The main point of what we are saying is that we don't really have enough data to know either way what would have happened to the dinosaurs," Bonsor said. "Generally in the fossil record there is a bias towards a lack of data, and to interpret those gaps in the fossil record as an artificial decline in diversification rates isn't what we should be doing.
"Instead we've shown that there is no strong evidence for them dying out, and that the only way to know for sure is to fill in the gaps in the fossil record," he added.
Alfio Alessandro Chiarenza, a palaeontologist at Imperial College London, who was not involved in the research, told CNN in an email that the study "applies probably the largest dataset of dinosaur evolutionary trees ever and applies thorough methods to look at diversification rates towards the end of the Mesozoic."
He noted that the research added weight to the argument that non-avian dinosaurs were thriving, not dwindling, before the asteroid hit.
"To paraphrase TS Eliot," Chiarenza said, "This is the way dinosaurs ended, not with a whimper but with a bang."
Why do researchers completely ignore the possibility that mammals
may have been a factor in the extinction of the dinosaurs some 65 mya?
Instead, they say that mammals and dinosaurs co-existed throughout the
Jurassic and Cretaceous and that this demonstrates that mammals did not
consume the Dinosaur young leading to the demise of that group. I remember
this theory from a 1950's textbook.
Giant reptiles (turtles) have "ruled" the Galapagos islands for a long
time. It is my understanding that recently imported dogs and cats have
caused a decline in the turtle population due to their predation of turtle
hatchlings. The same predation has also reduced the population of the other
Galapagos "rulers", the Iguanas. Why is it not a feasible possibility that
newly evolved (Late Cretaceous that is) placental mammals damaged the
dinosaur population by eating their young. The adult Dinosaurs (just like
adult Galapagos turtles) would be invulnerable to mammal attack but their
young would not be so lucky. Question--- When did definable placental
mammals evolve? Was it not in the Late Cretaceous, at about the same time
that the number of Dinosaur species declined?
Newly imported mammal species also exterminated the "rulers" of Mauritius,
the Dodos, some 3 centuries ago and seem to be doing the same today to the
ruling Tuataras, Kiwis and Parrots of New Zealand. In addition, it is my
understanding that the largest predator of the Paleocene (post Dinosaur)
was the 2 metre tall Diatryma which was eventually superseded by mammalian
Creodonts and true carnivores. Is my understanding correct? If Diatryma was
destroyed by placental mammal competition why not Troodonts or Velociraptors.
I do not claim that mammals were the sole or even a major cause of Dinosaur
extinction. I believe that it was a factor and should not be summarily dismissed.
Dinosaurs would have continued to thrive had it not been for the asteroid, researchers say
edition.cnn.com/2020/11/18/world/dinosaur-extinction-intl-scli-gbr-scn/index.html
By Amy Woodyatt, CNN
Updated 1555 GMT (2355 HKT) November 18, 2020
(CNN)Dinosaurs were doing well and could have continued to dominate Planet Earth if they had not been wiped out by an asteroid, new research has found.
After emerging during the Triassic period some 230 million years ago, dinosaurs occupied every continent and were dominant in most terrestrial ecosystems, until they were rendered extinct by the asteroid impact 66 million years ago.
Some scientists believe the creatures were beginning to lose their edge and were already heading for extinction when the asteroid hit Earth at the end of the late Cretaceous period.
But researchers from the UK's University of Bath are hoping to put this theory to bed. Gathering diverse and up-to-date data, researchers used statistical analysis to assess whether the dinosaurs were still able to produce new species up until their untimely demise.
An artist's interpretation of the asteroid impact that wiped out all non-avian dinosaurs
"What we found is that the dinosaurs were still dominant, they were still widespread and still doing really well," Joe Bonsor, first author of the study, said in a statement.
"If the asteroid impact had never happened then they might not have died out and they would have continued after the Cretaceous," Bonsor, a PhD student at London's Natural History Museum and the Milner Centre for Evolution at the University of Bath, added.
During their more than 150 million years on earth, dinosaurs evolved to take many shapes and forms -- some dinosaurs were tiny, while others measured over 100 feet. Experts think diversity was the key to their dominance on Earth, with some boasting armors, crests, teeth and even feathers.
Previous research had suggested that this diversity was starting to decline, and that dinosaurs were beginning to lose their dominance.
But the study published Tuesday in the journal The Royal Society Open Science argues that the earlier research reached this conclusion by modeling dinosaur family trees based on previous fossil records.
The University of Bath researchers say that, after looking at a greater number of dinosaur groups, their more up-to-date and detailed family trees show that dinosaurs on every continent were in fact flourishing, with plant-eating animals such as hadrosaurs, ceratopsians and ankylosaurs dominant in North America, and carnivorous abelisaurs continuing to thrive in South America.
"The main point of what we are saying is that we don't really have enough data to know either way what would have happened to the dinosaurs," Bonsor said. "Generally in the fossil record there is a bias towards a lack of data, and to interpret those gaps in the fossil record as an artificial decline in diversification rates isn't what we should be doing.
"Instead we've shown that there is no strong evidence for them dying out, and that the only way to know for sure is to fill in the gaps in the fossil record," he added.
Alfio Alessandro Chiarenza, a palaeontologist at Imperial College London, who was not involved in the research, told CNN in an email that the study "applies probably the largest dataset of dinosaur evolutionary trees ever and applies thorough methods to look at diversification rates towards the end of the Mesozoic."
He noted that the research added weight to the argument that non-avian dinosaurs were thriving, not dwindling, before the asteroid hit.
"To paraphrase TS Eliot," Chiarenza said, "This is the way dinosaurs ended, not with a whimper but with a bang."
