Name these rocks

a hard and tough rock that contains large crystals.

a hard and strong rock with thin, flattened crystals packed tightly together.

a brittle rock that contains fine grains and layers with fossil remains.

a hard black rock with small crystals

Even though the ostrich is a flightless bird, ostriches still possess wings that stretch approximately two meters across when fully extended. scientists speculate that when dinosaurs became extinct, some of the birds that lived during that time became land dwellers since they were able to consume the food that the dinosaurs once ate. over time, these species grew larger and heavier. eventually, the ostrich species became too big to fly. the wings found on ostriches are known as a. analogous structures. b. homologous structures. c. vestigial structures. d. symmetrical structures.