Ecology of Solnhofen Formation and similar environments

[Derdadort]

As said in the SVP topic the new thread for the European limestone, especially of Germany and France. For those, who don't know the Middle European limestone is a marine deposit of a former archipelago dating back to the Upper Jurassic. It's known for its great biodiversity of marine lifeforms, but especially the Solnhofen formation in Germany is also famous for its small theropods, namely Compsognathus, Juravenator, Sciurumimus, Wellnhoferia and Archaeopteryx.

Due to the fact I don't post so much in other topics, I can post here a bit more instead. It's after all my "home formation"


creature said:

I am not sure, but could this maybe hint a strong reproduction (R strategy) in small German theropods?
I believe this explanation is weak, unless a high number of juveniles is also observed among their relatives, just an idea.

Honestly, I think dinosaurs were or are still more r-strategists than K-strategists. The amount of the eggs is quite big, not as big as in amphibians and arthropods, but at least more juvenils than in mammals.
But if this explains the high amount of immature specimens, I don't know. Maybe it's one of many reasons.

I could imagine that it's more likely for juveniles to get washed offshore, however this would only apply for the species with probably large adults like Juravenator and Sciurumimus. Nevertheless Ohmdenosaurus would be an example for a large dinosaur getting washed away from an island, even if there are hardly bones left.

[theropod]

In part reproduction is likely responsible. Your hypothesis looks like a sufficient explanation for the rest actually.

Given that there are both considerably more immature individuals and that these are more likely to be preserved in the Solnhofen limestone, that explains why there are so many immature specimens there.

[creature386]

I guess we can agree that it is a mixture between preservational likelyhood, maybe also preservational bias and reproduction strategies

[Derdadort]

Yes, sounds to be the most likely scenario.
I also had the idea of a coastal based ecological niche for the immatures, but I doubt it honestly, because this would be some kind of coincidence for five different species after all. Additionally it's already proven that the German Compsognathus specimen fed on lizards.

(apart from that it's a bit difficult not to enter the coast when you live on an island...)

[Derdadort]

Wow, there is the topic I made a year ago^^

One new idea based on the pterosaurs of the Solnhofen Formation and similar deposits. Most of the specimens are also immature, additionally pterosaurs are more common (the most common terrestrial vertrebrates found in Solnhofen), so suit more for a hypothesis. A popular idea for the great number of fossils in Solnhofen are storms which on the one hand mixed the habitable surface near water layers in the lagoons with the hypersaline bottom near layers causing a mass mortality and on the other hand caused a slumping of lime mud from the sea into the lagoons, which finally results in the well preserved fossils we find today.
For pterosaurs it's also hypothesized that seasonal mass mortalities are responsible for the great number of immature specimens as well as different "size classes". Have therefore a closer look at this: www.jstor.org/stable/1306329?seq=1#page_scan_tab_contents

So probably the dinosaurs of Solnhofen were also effected of these seasonal mass mortalities with preservation bias for piscivore pterosaurs.

P.S. I change the topics name for a more precise one.