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Re: Mesozoic birds made insects shrink
Well, the birds and pterosaurs really didn't overlap much in terms of
size and niche, but it would make sense that even early birds could
push similar-sized pterosaurs to the edge of extinction, unless the
pterosaurs became specialized like the Anurognathids. There are fewer
and fewer of the little ptero's as the Cretaceous progresses and
birds establish themselves, which could have happened quite early.
Look at *Nemicolopterus* for a possible example of this.
...if *Nemicolopterus* isn't actually a baby *Sinopterus*, that is.
And what really small adult pterosaurs are there known from the
Jurassic? *Pterodactylus* grew up to reach a wingspan of 2.5 m,
*Rhamphorhynchus* was similar. All I can think of are the anurognathids,
and those survived into the Early Cretaceous quite well.
What is more, anurognathids are _only_ known from the few sites with the
most exceptional preservation. No such sites are known from the Late
Cretaceous at all. We have no idea when between the Jiufotang Formation
(Aptian) and Messel or the Green River Formation (early to middle
Eocene) the anurognathids went extinct.