Undergrad Dinosaur question -- Was Earth's gravity lower in the past?

[GregM]

Hello everyone,
I have researched about dinosaurs and pterosaurs and a theory by various authors claiming the only way to explain their great size is with ancient lower Earth gravity . If this is supported theory among scientists then the next question is: How could the Earth have lower gravity? One idea I've had is as the Earth cooled it also shrunk and therefore by the inverse square law the same mass would have stronger surface gravity. However it seems unlikely the Earth shrunk so much in 100 million years, also if the Earth was much larger in the past, wouldn't shrinking cause a massive speed up in spin rotation? The Earth may had very long days in the past.
Can it have happened this way? Or is there a better simpler theory of why the dinos got so large? Any links to acedemic debates and conclusions on this question?
Thanks

 

[pinball1970]

I would look into the climate side of things. Temperature, O2 CO2 levels.
@jim mcnamara @BillTre very knowledgeable on this

 

[Herman Trivilino]

I have researched about dinosaurs and pterosaurs and a theory by various authors claiming the only way to explain their great size is with ancient lower Earth gravity .

Do you have references for these claims?

 

[phinds]

I have researched about dinosaurs and pterosaurs and a theory by various authors claiming the only way to explain their great size is with ancient lower Earth gravity

Here of PF it is not acceptable to say "I read that ... " (or your "I have researched ... " . You have to provide specific citations from refereed journals otherwise we might just be discussing nonsense.

 

[berkeman]

Thread closed for Moderation...

 

[berkeman]

Thread will remain closed. @GregM -- check your PMs. You may start a new thread about this question if you can find links to peer-reviewed journal articles about your question.