Some birds were scavengers, but the survival of many lineages is a puzzle. In unfavorable conditions some may take a long time to develop: there is a record of a beetle larva living in dead wood for over 40 years before becoming an adult. Many insects feed on dead material furthermore, most have at least one resting stage in which they are very resistant to damage. Indeed, with the deaths of so many other animals and with much dead plant material, the food chain based on detritus would have been well-supplied. The two first named are known to be able to survive for long periods without food, and both can be scavengers (feed on dead material). Crocodiles, tortoises, birds, and insects seem to have been little affected. Furthermore, it is most likely that these large dinosaurs had slow rates of reproduction, which always increases the risk of extinction. These leaves were the food of some of the mammals and of the herbivorous dinosaurs, which in turn were fed on by the carnivorous dinosaurs. As in the sea, it seems that on the land one key food chain collapsed: the one with leaves as its basic raw material. For example, in North America 79 percent did not survive, and it has been noted that the survivors were often deciduous they could lose their leaves and shut down while others could survive as seeds. The mammals, most of which were small, lost some 35 percent of their species worldwide. Paragraph 2: On land it was not only the large animals that became extinct.

The foundation of the major marine food chain that led from the minute plankton to shelled animals to large marine reptiles had collapsed. The microscopic plankton (free-floating plants and animals) with calcareous shells suffered massively. Paragragh 1: It has long been recognized that the dinosaurs disappeared from the fossil record at the end of the Cretaceous period (65 million years ago), and as more knowledge has been gained, we have learned that many other organisms disappeared at about the same time.

Tpo toefl answer key