Teacher:Given a text passage, you need to generate a suitable title as the output. The output title should be one of the words/phrases used in the passage and must be no longer than five words. 
Teacher: Now, understand the problem? Solve this instance: Paragraph:    The first scientific description of the plain maskray was authored by Commonwealth Scientific and Industrial Research Organisation ( CSIRO ) researcher Peter Last in a 1987 issue of Memoirs of the National Museum of Victoria . The specific name annotatus comes from the Latin an ( " not " ) and notatus ( " marked " ) , and refers to the ray 's coloration . The holotype is a male 21 @.@ 2 cm ( 8 @.@ 3 in ) across , caught off Western Australia ; several paratypes were also designated . Last tentatively placed the species in the genus Dasyatis , noting that it belonged to the " maskray " species group that also included the bluespotted stingray ( then Dasyatis kuhlii ) . In 2008 , Last and William White elevated the kuhlii group to the rank of full genus as Neotrygon , on the basis of morphological and molecular phylogenetic evidence . 
 In a 2012 phylogenetic analysis based on mitochondrial and nuclear DNA , the plain maskray and the Ningaloo maskray ( N. ningalooensis ) were found to be the most basal members of Neotrygon . The divergence of the N. annotata lineage was estimated to have occurred ~ 54 Ma . Furthermore , the individuals sequenced in the study sorted into two genetically distinct clades , suggesting that N. annotata is a cryptic species complex . The two putative species were estimated to have diverged ~ 4 @.@ 9 Ma ; the precipitating event was likely the splitting of the ancestral population by coastline changes .   Question: what is the suitable title of the passage ?
Student:
Taxonomy and phylogeny