Liky Posted June 23, 2018 Share Posted June 23, 2018 Considering the length of time they lived it seems there are not just too few but unbelievably few species that people have discovered, don't you agree ? Also this leads me to the question which I could not find an answer to in google... that must mean something. How did the biological variety change though the course of the planets history. Is there a way we can know, were there more animal and plant species 1, 10, 100 million years ago? Link to comment Share on other sites More sharing options...
talon22 Posted June 23, 2018 Share Posted June 23, 2018 Without a doubt. Considering that with birds alive today, there are over 10,000 species known (the living dinosaurs), it is very unlikely that in over 150 million years only a couple of thousands of non-avian dinosaur taxa existed. Since fossils are what we go by, they really only represent a small portion of the dinosaurs that existed in various ecosystems. The truth is we will never know exactly how many species were around and many species will never be discovered as there remains didn't fossilize for us to find while many more await discovery - and some fossils may represent new species but are currentlly labelled as belonging to a well know genera/species (sometimes referred to as a wastebucket taxon). Pterosaurs are even more poorly known, since they had such fragile/hollow bones, only around 120 species are currently know for a group that existed around as long as the non-avian dinosaurs........ makes me wonder hypothetically if in the future another highly intelligent species will discover a small amount of bird fossils and think they were a rarity in the present age. Link to comment Share on other sites More sharing options...
Troodon Posted June 23, 2018 Share Posted June 23, 2018 A model was actually constructed to try to determine the number of species that existed. So this is their scientific answer. Using TRiPS their model, they estimated that 1936 (1543–2468) species of dinosaurs roamed the Earth during the Mesozoic. Total species richness for the subclades is estimated to be 508 (409–668) for Ornithischia, 513 (307–983) for Sauropodomorpha and 1115 (780–1653) for Theropoda How many dinosaur species were there? Fossil bias and true richness estimated using a Poisson sampling model Jostein Starrfelt, Lee Hsiang Liow Published 14 March 2016.DOI: 10.1098/rstb.2015.0219 http://rstb.royalsocietypublishing.org/content/371/1691/20150219 PLOS Blog on the paper which is a much eadier read than the paper http://blogs.plos.org/paleocomm/2016/03/30/how-many-dinosaurs-were-there/ Chart depecting number of species through time Link to comment Share on other sites More sharing options...
Auspex Posted June 23, 2018 Share Posted June 23, 2018 2 hours ago, talon22 said: Considering that with birds alive today, there are over 10,000 species known (the living dinosaurs), it is very unlikely that in over 150 million years only a couple of thousands of non-avian dinosaur taxa existed. If you factor in that an animal's size plays a controlling roll in how many species like it can coexist, and that large animals reproduce more slowly than small (greatly diminishing radiative evolution), it is not surprising that the number of modern avian theropod species is so high compared to that of megafauna. Think in terms of "pounds per acre". "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
Troodon Posted June 24, 2018 Share Posted June 24, 2018 Dinosaur paleobilogist Thomas Holtz's, on-going chart of dinosaur species (Mesozoic dinosauromorphs, to be exact) named from 2003 onward The average for 2003-2017 is 45, so nearly 1 per week. Link to comment Share on other sites More sharing options...
TyBoy Posted June 25, 2018 Share Posted June 25, 2018 On 6/23/2018 at 5:04 PM, Troodon said: Dinosaur paleobilogist Thomas Holtz's, on-going chart of dinosaur species (Mesozoic dinosauromorphs, to be exact) named from 2003 onward The average for 2003-2017 is 45, so nearly 1 per week. Interesting chart the average of 1 per week it's pretty remarkable Link to comment Share on other sites More sharing options...
Troodon Posted June 25, 2018 Share Posted June 25, 2018 Probably biased with a huge 2010. 40 per year looks more a nominal rate Link to comment Share on other sites More sharing options...
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