pterosaurs were believed to be the direct ancestors to birds.
pterosaurs were believed to be the direct ancestors to birds.
who are believed to be the direct ancestors to birds?
pterosaurs
Na
Na
darwin noted that transitional forms could be considered common ancestors, direct ancestors or collateral ancestors of living or extinct groups, but believed that finding actual common or direct ancestors linking different groups was unlikely. collateral ancestors are relatives like cousins in genealogies in which they are not in your direct line of descent but do share a common ancestor (in this case it is a grandparent). this kind of thinking can be extended to groups of life. for instance, the well-known "archaeopteryx" is a transitional form between non-avian dinosaurs and birds, but it is not the most recent common ancestor of all birds nor is it a direct ancestor of any species of bird alive today. rather, it is considered an extinct close evolutionary "cousin" to the direct ancestors. this may not always be the case, though, as some fossil species are proposed to be directly ancestral to others, like how "australopithecus anamensis" is most likely to be ancestral to "australopithecus afarensis".
list of transitional fossils