researchers, but is generally agreed on to be the result of several ‘pulses’, or miniature... ... middle of paper ... ...turwissenschaften, Volume 97, Issue 2 4.) Jessica Amber Camp (2010), Morphological variation and disparity in Lystrosaurus (Therapsida: Dicynodontia), University of Iowa 5.) Peter D. Wardotha, Roger Black, Michiel O. De Kock, Douglas E. Erwin, Geoffrey H. Garrison, Joseph L. Kirschvink, Roger Smith (2005), Abrupt and Gradual Extinction Among Late Permian Land Vertebrates in the