Why were Cynognathus fossils were impostor Wegener theory
There seems to be some misunderstanding in your question. Cynognathus fossils were not impostors of Wegener's theory. In fact, the discovery of Cynognathus fossils played a significant role in supporting Wegener's theory of continental drift.
During the early 20th century, Alfred Wegener proposed the idea that the continents were once connected as a single landmass called Pangaea, which gradually drifted apart over time. This theory was initially met with skepticism and faced many challenges.
However, one of the supporting pieces of evidence for Wegener's theory came from the discovery of Cynognathus fossils. Cynognathus is an extinct reptile-like mammal that lived during the Late Triassic period. Fossils of Cynognathus were found in Africa, South America, and Antarctica, which are currently widely separated continents.
The presence of identical or closely related fossils in different continents suggested that these landmasses were once connected and supported the idea of continental drift. This finding helped to strengthen Wegener's case for his theory and eventually led to the development of the modern theory of plate tectonics.