what was the geology like during that period?
Large igneous provinces.
Early Cretaceous
There is a possible link between this anoxic event and a series of Early Cretaceous large igneous provinces (LIP).
what is acamptonectes? It is an extinct genus of ophthalmosaurid ichthyosaur. what did they eat? Fish and squid. where were their fossils discovered? England and Germany. to which period did these fossils date back to? Early Cretaceous period.
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Early Cretaceous [SEP] Geology
Proposals for the exact age of the Barremian-Aptian boundary ranged from 126 to 117 Ma until recently (as of 2019), but based on drillholes in Svalbard the defining early Aptian Oceanic Anoxic Event 1a (OAE1a) was carbon isotope dated to 123.1±0.3 Ma, limiting the possible range for the boundary to c. 121–122 Ma. There is a possible link between this anoxic event and a series of Early Cretaceous large igneous provinces (LIP). The Ontong Java-Manihiki-Hikurangi large igneous province, emplaced in the South Pacific at c. 120 Ma, is by far the largest LIP in earth's history. The Ontong Java Plateau today covers an area of 1,860,000 km².