【英语翻译Whalesthatsufferthebendsoftendosobecausetheyhavesurfacedtoescapeapredator（捕食动物）suchasalargeshark.OneofthefeaturesofJurassicoceanswasanabundanceoflargesharksandcrocodiles,bothofwhichwerefond】

　　英语翻译

　　Whalesthatsufferthebendsoftendosobecausetheyhavesurfacedtoescapeapredator（捕食动物）suchasalargeshark.OneofthefeaturesofJurassicoceanswasanabundanceoflargesharksandcrocodiles,bothofwhichwerefondofichthyosaurlunches.【Triassicoceans,bycontrast,weremercifullyshark-andcrocodile-free.IntheTriassic,then,ichthyosaursweretopofthefoodchain.IntheJurassicandCretaceous,theywereprey（猎物）aswellaspredator—andoftenhadtomakeaspeedyexitasaresult.】

　　请分析【】里的句子结构,我觉得很乱,然后标准翻译一下,