Longitudinal fissure Longitudinal fissure The longitudinal fissure (or cerebral fissure, median longitudinal fissure, or interhemispheric fissure) is the deep groove that separates the two hemispheres of the vertebrate brain. The medial surfaces of the two hemispheres are as similarly convoluted by gyri and sulci as is the outer surface of the brain. It is thought that a majority of existing animals, including Homo sapiens, have evolved from a common wormlike ancestor that lived around 600 million years ago, called the urbilaterian. A bilaterian animal is one that has symmetrical left and right body halves. While it is still debated whether this species
Conard Fissure Conard Fissure The Conard Fissure is a geologic feature in Northern Arkansas where a deposit of Pleistocene fossils was discovered in 1903. Several specimens from saber-toothed cats were found there among other species. The fissure is located near the Buffalo National River in Boone County, Arkansas, approximately 15 miles south of the town of Harrison. It lies approximately one mile north of the river near the border of Newton and Boone County. The fissure is named after Waldo Conard who owned the land that the fissure is situated on. The original excavation of the Conard Fissure was performed by Barnum