Baringochromis senutae, Baringochromis sonyii, and Baringochromis tallamae: Three new species of Cichlid Fish from the upper Miocene of the palaeolake Waril in Central Kenya.
[sciencythoughts.blogspot.com]
The tropical freshwater Fish family Cichlidae and its estimated 2285 species is famous for its high degree of phenotypic diversity, trophic adaptations and specialised behaviors, and represents an established model in studies dealing with evolutionary processes. The monophyly of the family is well supported by morphological and molecular data, but most morphological synapomorphies (characteristics present in an ancestral species and shared exclusively, in more or less modified forms, by its evolutionary descendants) relate to soft tissue or delicate bone structures, which are rarely preserved in fossils. The only Cichlid apomorphy (character that is different from the form found in an ancestor) with a relatively high potential to be well preserved in the fossil record is related to their saccular otoliths (‘ear stones', which display a specific ornament termed the ‘anterocaudal pseudocolliculum’ on their mesial surface. Fortunately, modern Cichlid fishes also possess several morphological traits that typify them. These include: a bipartite lateral line, a specific composition of the caudal skeleton and fin (i.e. eight principal caudal fin rays in each lobe, two epural bones, uroneural and parhypural each autogenous, preural centrum 2 with autogenous haemal spine and reduced neural spine, preural centrum 3 with fused haemal spine), a single dorsal fin consisting of spines and rays, a pelvic fin with one spine and five rays, and a hyoid bar with five branchiostegals. It is essentially this combination of characters that enables one to identify a fossil Fish as a Cichlid.