Some land plants and arthropods like trilobites existed before the dianosaurs existed on Earth.
Step-by-step explanation:
The first reptiles are reported to have appeared during the Carboniferous period. The Dinosaurs were large reptiles that became dominant during the triassic and jurassic. By the end of cretaceous the dinosaurs became extinct.
In the given options we find that some land plants and trilobites are suitable choice because, firstly, the fossil plants are recorded during carboniferous period and some of those species became extinct before the appearance of dinosaurs. Secondly, trilobites became extinct by the end of permian period.
Rest of the options like birds, mammals, etc came into existence before dinosaurs but they continued to exist along with dinosaurs.