Fossils of thrinaxodon, a species that lived during the triassic period, have been found in both south africa and antarctica. thrinaxodon had a reptile-like skeleton and laid eggs, but small depressions on the front of its skull suggest it had whiskers and, therefore, fur. thrinaxodon may have been warm-blooded. the fossils of thrinaxodon are consistent with the hypothesis that ) fossils found in a given area look like the modern species in that same area
b) the environment where it lived was very warm
c) mammals evolved from a reptilian ancestor
d) antarctica and south africa separated after thrinaxodon went extinct

C) mammals evolved from a reptilian ancestor

Explanation:

Mammals, amphibians, and reptiles are tetrapods. Reptiles and mammals are shown to be originated from a common ancestor, the early tetrapods which in turn diversified into two lineages. One of the lineages evolved into synapsids and the other gave rise to reptiles and birds. Synapsids diversified into two lineages one of which later formed mammals.

According to the given information, fossil records of Thrinaxodon have a reptile-like skeleton and were oviparous like reptiles. However, the presence of furs and the possibility of being warm-blooded make it like a mammal.

Reptiles are cold-blooded egg-laying tetrapods while mammals are warm-blooded viviparous tetrapods. The presence of some of the features from both the groups in Thrinaxodon provides proof that mammals evolved from a reptilian ancestor.

c. earths continental crust is thicker than its lithosphere.

because, the lithosphere is the outermost layer of the earth/ 100 km thick and is defined by its machanical properties.the lithosphere contains oceanic and continental crust that varies in age and thickness across locations and geologic time. the lithosphere is the coolest layer of the earth in terms of temperature. the term lithosphere should not be confused with the use of "geosphere" which is used to indicate all of earth systems, including the atmosphere, hydrosphere   and biosphere. the surface of the earth can be divided into the continental crust and the oceanic crust.   the continental crust is made mostly of granite while the oceanic crust is made of basalt. the average thickness of the continental crust is 25 miles and the average thickness of the oceanic crust is 5 miles.   three types of rock, igneous, sedimentary, and metamorphic, make up the surface of the earth. that's why 3 option is preferable.