By . Sarah Griffiths . Paleontologists have long pondered what caused the extinction of the dinosaurs 66 million years ago and came up with some crazy theories. While a spy proposed the dinosaurs suffered from overactive glands and a low sex drive, which led to their downfall, other scientists believed growing too big, hungry caterpillars, aliens and a taste for eggs were all good reasons as to why the ancient beasts died out. Now-a-days most scientists agree a combination of volcanic activity, climate change and a massive asteroid impact probably finished off  land-dwelling dinosaurs - with the exception of birds. While a spy proposed the dinosaurs suffered from overactive glands and a low sex drive which led to their downfall, other scientists believed growing too big, hungry caterpillars, aliens and even farting were all good reasons as to why the ancient beasts died out . A spy and Hungarian-born aristocrat, Baron Franz Nopcsa von Felső-Szilvás, had plenty of extinction theories in the early 20th century including that dinosaurs had a low sex drive and overactive glands. The keen paleontologist thought dinosaurs got so large because of secretions from the pituitary gland, which caused them to grow too large. While he tried to apply knowledge of human conditions to the dinosaurs, there is no evidence to suggest that the gland had anything to do with the animals' size or extinction, Smithsonian reported. Another scientist living at the same time, called George Wieland, believed the dinosaurs ate themselves to death and the T-Rex got its 'first impulse toward gigantism on a diet of sauropod eggs'. The Yale researcher said the greedy carnivores ate too many eggs and caused their mass extinction, but now-a-days scientists agree that while fossils show the creatures had a taste for eggs, they could not have eaten them all. Staying with eggs, fossil expert H.K. Erben proposed in the 1970s that dinosaur eggs had multiple shell layers, while others were too thin, causing developing dinosaurs to either suffocate, or dehydrate if the shell was too thin and got broken. One researcher said greedy dinosaurs ate too many eggs to cause mass extinction, but now-a-days scientists agree that while fossils show the creatures had a taste for eggs, they could not have eaten them all. A nest of petrified dinosaur eggs being analysed is pictured . While he based his idea on eggshells found in Southern France, fossil records show this was a local phenomenon and not a widespread problem. In the early 1900s, when Darwin's theory of natural selection was still catching on, many palaeontologists thought the beasts became too sluggish, big and stupid to function. The now unpopular theory supposed that dinosaurs had a kind of evolutionary inertia and spent their energy getting larger instead of smarter, despite the fact that some of the largest species of dinosaur including the Stegosaurus and Brachiosaurus thrived. More recently, in the past decade, an infertility specialist has argued the dinosaurs died out as they couldn't find partners. Sherman Silber said that as temperatures can determine the sex of some animals, like crocodiles, climate change could have ensured that only one sex of dinosaur babies were born. There are several holes in this theory including that scientists do not know if the sex of dinosaurs were determined by temperature. In the 1960s, entomologist Stanley Flanders proposed that the first moths and caterpillars ate all the vegetation on Cretaceous Earth, causing the herbivorous dinosaurs to go hungry. In the 1960s by entomologist Stanley Flanders proposed that the first moths, butterflies and caterpillars ate all the vegetation on Cretaceous Earth, causing the herbivorous dinosaurs to go hungry. A modern  Pearl-bordered fritillary butterfly is pictured . Consequently he argued the predators would also starve as they had no more vegetarian dinosaurs to eat. However, once again, modern science and fossil records have shown that butterflies and moths happily coexisted with dinosaurs and did not gobble all the plants. The Smithsonian article notes that as the expertise of scientists often informs their theory, it is not surprising that ophthalmologist L.R. Croft believed bad eyesight was to blame for the extinction of the dinosaurs. In the 1980s he said rising temperatures caused cataracts to develop faster and even went as far to suggest that dinosaurs successfully evolved horns on their faces to protect their eyes from the sun. The theory does not explain why flying dinosaurs did not go blind too. While not strictly a scientific idea, last year paleontologist David Wilkinson speculated the dinosaur's annual . output of methane gas would have been enough to cause global warming. Before the idea of an asteroid impact (pictured) was embraced by the scientific community as a reason for the extinction of dinosaurs, physicist Wallace Tucker and paleontologist Dale Russell suggested in the 1970s that a death blow came from space . While they did not mention extinction, the media seized upon the idea to conclude dinosaurs farted themselves to death. Likewise, a TV programme last year called 'Ancient Aliens' amalgamated various scraps of science to state that aliens could have wiped out the dinosaurs. However, Utah State University’s Prehistoric Museum said there is no evidence to suggest this theory is true as no fossilized aliens, or alien waste has ever been discovered. Finally, before the idea of an asteroid impact was embraced by the scientific community as a reason for the extinction of dinosaurs, physicist Wallace Tucker and paleontologist Dale Russell suggested in the 1970s that a death blow came from space. However, they thought a supernova relatively close to the Earth exploded and bombarded the upper atmosphere with X-rays causing temperatures to decrease sharply. But no evidence of an astronomical event has been found. They thought a supernova relatively close to the Earth exploded and bombarded the upper atmosphere with X-rays causing temperatures to decrease sharply. But no evidence of an astronomical event has been found. A supernova called Cassiopeia is pictured .
Spy and paleontologist Baron Franz Nopcsa thought dinosaurs had overactive glands and low sex drives and dies out as a result .
Entomologist Stanley Flanders proposed caterpillars ate all the vegetation on Cretaceous Earth, causing the herbivorous dinosaurs to go hungry .
Ophthalmologist L.R. Croft believed bad eyesight was to blame for the extinction of the dinosaurs as they developed cataracts .
By . Sarah Griffiths . Paleontologists have long pondered what caused the extinction of the dinosaurs 66 million years ago and came up with some crazy theories. While a spy proposed the dinosaurs suffered from overactive glands and a low sex drive, which led to their downfall, other scientists believed growing too big, hungry caterpillars, aliens and a taste for eggs were all good reasons as to why the ancient beasts died out. Now-a-days most scientists agree a combination of volcanic activity, climate change and a massive asteroid impact probably finished off  land-dwelling dinosaurs - with the exception of birds. While a spy proposed the dinosaurs suffered from overactive glands and a low sex drive which led to their downfall, other scientists believed growing too big, hungry caterpillars, aliens and even farting were all good reasons as to why the ancient beasts died out . A spy and Hungarian-born aristocrat, Baron Franz Nopcsa von Felső-Szilvás, had plenty of extinction theories in the early 20th century including that dinosaurs had a low sex drive and overactive glands. The keen paleontologist thought dinosaurs got so large because of secretions from the pituitary gland, which caused them to grow too large. While he tried to apply knowledge of human conditions to the dinosaurs, there is no evidence to suggest that the gland had anything to do with the animals' size or extinction, Smithsonian reported. Another scientist living at the same time, called George Wieland, believed the dinosaurs ate themselves to death and the T-Rex got its 'first impulse toward gigantism on a diet of sauropod eggs'. The Yale researcher said the greedy carnivores ate too many eggs and caused their mass extinction, but now-a-days scientists agree that while fossils show the creatures had a taste for eggs, they could not have eaten them all. Staying with eggs, fossil expert H.K. Erben proposed in the 1970s that dinosaur eggs had multiple shell layers, while others were too thin, causing developing dinosaurs to either suffocate, or dehydrate if the shell was too thin and got broken. One researcher said greedy dinosaurs ate too many eggs to cause mass extinction, but now-a-days scientists agree that while fossils show the creatures had a taste for eggs, they could not have eaten them all. A nest of petrified dinosaur eggs being analysed is pictured . While he based his idea on eggshells found in Southern France, fossil records show this was a local phenomenon and not a widespread problem. In the early 1900s, when Darwin's theory of natural selection was still catching on, many palaeontologists thought the beasts became too sluggish, big and stupid to function. The now unpopular theory supposed that dinosaurs had a kind of evolutionary inertia and spent their energy getting larger instead of smarter, despite the fact that some of the largest species of dinosaur including the Stegosaurus and Brachiosaurus thrived. More recently, in the past decade, an infertility specialist has argued the dinosaurs died out as they couldn't find partners. Sherman Silber said that as temperatures can determine the sex of some animals, like crocodiles, climate change could have ensured that only one sex of dinosaur babies were born. There are several holes in this theory including that scientists do not know if the sex of dinosaurs were determined by temperature. In the 1960s, entomologist Stanley Flanders proposed that the first moths and caterpillars ate all the vegetation on Cretaceous Earth, causing the herbivorous dinosaurs to go hungry. In the 1960s by entomologist Stanley Flanders proposed that the first moths, butterflies and caterpillars ate all the vegetation on Cretaceous Earth, causing the herbivorous dinosaurs to go hungry. A modern Pearl-bordered fritillary butterfly is pictured . Consequently he argued the predators would also starve as they had no more vegetarian dinosaurs to eat. However, once again, modern science and fossil records have shown that butterflies and moths happily coexisted with dinosaurs and did not gobble all the plants. The Smithsonian article notes that as the expertise of scientists often informs their theory, it is not surprising that ophthalmologist L.R. Croft believed bad eyesight was to blame for the extinction of the dinosaurs. In the 1980s he said rising temperatures caused cataracts to develop faster and even went as far to suggest that dinosaurs successfully evolved horns on their faces to protect their eyes from the sun. The theory does not explain why flying dinosaurs did not go blind too. While not strictly a scientific idea, last year paleontologist David Wilkinson speculated the dinosaur's annual . output of methane gas would have been enough to cause global warming. Before the idea of an asteroid impact (pictured) was embraced by the scientific community as a reason for the extinction of dinosaurs, physicist Wallace Tucker and paleontologist Dale Russell suggested in the 1970s that a death blow came from space . While they did not mention extinction, the media seized upon the idea to conclude dinosaurs farted themselves to death. Likewise, a TV programme last year called 'Ancient Aliens' amalgamated various scraps of science to state that aliens could have wiped out the dinosaurs. However, Utah State University’s Prehistoric Museum said there is no evidence to suggest this theory is true as no fossilized aliens, or alien waste has ever been discovered. Finally, before the idea of an asteroid impact was embraced by the scientific community as a reason for the extinction of dinosaurs, physicist Wallace Tucker and paleontologist Dale Russell suggested in the 1970s that a death blow came from space. However, they thought a supernova relatively close to the Earth exploded and bombarded the upper atmosphere with X-rays causing temperatures to decrease sharply. But no evidence of an astronomical event has been found. They thought a supernova relatively close to the Earth exploded and bombarded the upper atmosphere with X-rays causing temperatures to decrease sharply. But no evidence of an astronomical event has been found. A supernova called Cassiopeia is pictured .
suffered from overactive glands and a low sex Franz Nopcsa von Felső-Szilvás, had plenty of caterpillars ate all the vegetation on Cretaceous Earth, causing the herbivorous dinosaurs to go Flanders proposed that the first moths, vegetation on Cretaceous Earth, causing the herbivorous dinosaurs to go hungry. A modern that ophthalmologist L.R. Croft believed bad eyesight was to blame for the extinction of the