Paper No. : 14 Human Origin and Evolution Module : 13 Ramapithecus: Phylogenetic and Taxonomic status Development Team Principal Investigator Prof. Anup Kumar Kapoor Department of Anthropology, University of Delhi Dr. Satwanti Kapoor (Retd Professor) Paper Coordinator Department of Anthropology, University of Delhi Ms. Sangeeta Dey & Prof. A.K. Kapoor Content Writer Department of Anthropology, University of Delhi Prof. R.K. Pathak Content Reviewer Department of Anthropology, Panjab University, Chandigarh 1 Ramapithecus: Phylogenetic and Taxonomic status Anthropology Description of Module Subject Name Anthropology Paper Name Human Origin and Evolution Module Name/Title Ramapithecus: Phylogenetic and Taxonomic status Module Id 13 Contents: 1. Introduction 2. Ramapithecus 3. Significant anatomical characteristics of Ramapithecus 4. Discovery and distribution of Ramapithecus 5. Paleoanthopological evidence from India with special references to Siwaliks 6. Phylogenetic position of Ramapithecus 7. Controversy regarding the taxonomy of Ramapithecus Summary Learning Objectives: To describe the physical features of Ramapithecus To understand the Phylogenetic position of Ramapithecus To describe the fossil evidences recovered in the context of Ramapithecus To learn about the facts that leads to the evolutionary advancement of hominid line To understand the taxonomic status of Ramapithecus 2 Ramapithecus: Phylogenetic and Taxonomic status Anthropology 1. Introduction The geological time scale starts with the formation of the earth, some 4.6 billion years ago. The first and longest span of time was the pre-Cambrian, where forms of life were small, simple and soft-bodied. The onset of Cambrian about 570 million years ago marked the rise of shelled animals in the sea. Then followed the “ages” of the fish, Amphibians and Reptiles, culminating in the domination of land by the dinosaurs, from about 200 to 65 million years ago. Mammals first appeared more than 200 million years ago, but were overshadowed by the reptiles. However, some 65 million years ago all the dinosaurs – as well as other groups of reptiles on land, in the sea and in the air, and certain other animal groups and many plants too – became extinct over a relatively short period. This was only one of several “mass extinctions” that have occurred through geological time. The extinction marked the beginning of the Tertiary period and the Age of Mammals. The Tertiary is divided into epochs, and development in the primate group can be traced from the fossils they left in the rocks formed during the time. The first hominids (members of our family Hominidae) crop up in the fossil record less than million years ago. Mammalian evolution covers only about 4 percent of the Earth’s entire history, and humans have been around for only 0.1 percent of the history of our planet. The quest for our ultimate origins began with the origin of life itself. The earth is about 4.6 billion years old. Fossil evidence shows that small, simple organisms were living at least 3 billion years ago. A great deal of evidence supports the notion that all present day organisms are related to each other, and these forms as diverse as slime molds and elephants, oak trees and beetles, roses and humans – ultimately arose from a single common ancestor, some 3.5 billion years ago. This means that a single evolutionary tree or phylogeny, relates all organisms, living and extinct. Biologists and palaeontologists assume that life evolved from its simple beginnings through a succession of stages, as represented in the fossil record, toward the present day diversity of some 10 – 30 million 3 Ramapithecus: Phylogenetic and Taxonomic status Anthropology species. This does not mean that today’s diversity is in some way the destiny or the end point of evolution; there has been great diversity in the past, and there may be in the future. Source Link: https://www.google.co.in/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&ved=0ahUKEwjP2oi j_sPTAhUBrI8KHW74BywQjRwIBw&url=http%3A%2F%2Fwww.portal.gsi.gov.in%2Fpls%2Fp ortal%2Furl%2Fpage%2FGSI_STATIC%2FGSI_STAT_GEOLOGY_LIFE_AGES&psig=AFQjC NFsx3p8DjiWKjA4dY2wrzEn5hpFdw&ust=1493360154025061 2. Ramapithecus The last and most important hominid from Miocene period is the Ramapithecus. It is accepted by many scholars to be the first true hominid. Ramapithecus dates back to the period between 14 – 10 million years ago. It was discovered and christened as Rama’s ape by Edward Lewis in the year 1934. The specimen was later analyzed by Simons in the year 1964. Simons gave the name Ramapithecus punjabicus to this find, which was a long time thought to be the highest evolved form in the Hominid evolution, belonging to the ape group of Dryopithecus. The fossils of Ramapithecus (Primarily teeth and jaw) come from two areas: the Siwalik Hills in India and Fort 4 Ramapithecus: Phylogenetic and Taxonomic status Anthropology Ternan in Kenya. Other specimens have been discovered from Turkey, Hungary and Greece. The Ramapithecus fossils roughly date back to periods between 14 and 9 million years ago. The ecological setting of Fort Ternan and the Siwalik Hill fossils is that of a forest woodland environment. The Greek fossils, being younger, are that of a drier, savanna like environment. The hominid features of Ramapithecus include reduced and vertically implanted incisors, and canines, little or no diastema, flattened and thick enamelled premolars and molars that appear to be adapted for heavy chewing and processing of heavy food stuffs. Moreover, the placements of chewing muscles indicated an increased chewing pressure brought to bear on the food being eaten. These features, sufficiently different from the earlier Miocene fossils, indicate Ramapithecus direction to hominid line – perhaps the first hominid. Picture: Ramapithecus 5 Ramapithecus: Phylogenetic and Taxonomic status Anthropology Source Link: https://www.google.co.in/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ve d=0ahUKEwibtf- Bq8TTAhWFvo8KHVb2CAYQjRwIBw&url=https%3A%2F%2Fwww.thoughtco.com%2Fsivapit hecus-ramapithecus- 1093141&psig=AFQjCNHWiQO7dhmzNUQtEVDDl374o_S5JA&ust=1493372171588560 Ramapithecus specimens very strongly suggest the exploitation of a new dietary source – most likely seeds, nuts and grasses – that indicate a shift from the softer forest fruits and vegetables relied upon by apes. This dietary shift is rather clearly associated with the climatic changes in the later part of Miocene that led to an increase in open grasslands and the decrease in the forest habitat of apes. There is a greater probability that this hominid form apparently was moving into a new ecological niche; it was beginning to exploit a more open ground environment similar to that inhabited by later hominids. Ramapithecus is also the most likely candidate for the ancestry of later hominids because of its presence in an area where the next hominids – the Australopithecus - have been found. The possible adaptation that Ramapithecus made to open – ground living include an increased degree of hand and finger preparation of food, perhaps more frequent use of tools in such preparation, a tendency towards upright posture and bipedal locomotion for movement with a wide field of vision through the tall grasses on the open plain, possibly longer periods of growth and development, and perhaps, even a more frequent inclusion of meat in the diet. None of these adaptations can be clearly demonstrated because of lack of fossil evidences, but what we do know is that these adaptations were clearly present by the time the next phase of hominid evolution – the Australopithecus – had began. It is highly likely that Ramapithecus had begun to evolve and acquire those hominid features that led to the evolution of Australopithecus. 6 Ramapithecus: Phylogenetic and Taxonomic status Anthropology 3. Significant Anatomical Characteristics of Ramapithecus Facial profile of Ramapithecus is orthognathus that the profile is the face nearly vertical with straight jawed with the front of the head or skull is perpendicular in consequence of the shortness of the jaws. Ramapithecus has nearly vertical placement of incisors and canines opposite to apes which has teeth in slight procumbent position. Generally apes have projected canines with large spaces in between whereas Ramapithecus canines are not projected and they posses very narrow spaces. It has canine fossa or depression encountered in fossils Ramapithecus kenyapithecus. The gap between two teeth is usually referred as diastema and it is evident in apes whereas in Ramapithecus, little or no diastema was found. Source Link: https://www.google.co.in/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact =8&ved=0ahUKEwjSqMrbq8TTAhVLpo8KHQqWCqIQjRwIBw&url=http%3A%2F%2F 7 Ramapithecus: Phylogenetic and Taxonomic status Anthropology www.angelfire.com%2Fmi%2Fdinosaurs%2Fzramapithecus.html&psig=AFQjCNHWiQO7 dhmzNUQtEVDDl374o_S5JA&ust=1493372171588560 The size of the front teeth that is incisors and the canines to that of the cheek teeth that is premolars and molars is nearly the same which is an indication of human characteristics. The premolars and the molars due to the changed in food habits and because of adaptation from soft food to heavy chewing and grinding of hard food stuff led becomes flattening and deposited with thick enamel. The molars posses the Y-5 cusp pattern as in Dryopithecus. The size of the third molar is reduced as compare to the first and second molar. Tooth rows are slightly divergent and have been identified as parabolic or slightly V-shape by some scholars. Maxilla reduced in size which indicates a placement of the chewing muscles which actually increases the chewing pressures required to bear or chew the foods being eaten. Inside the lower jaw of Ramapithecus shelf –like ridges are present. There is a presence of large inferior torus on mandible Ramapithecus posses rounded dental arcade. Like humans, the palate of the Ramapithecus is arched. 8 Ramapithecus: Phylogenetic and Taxonomic status Anthropology 4. Discovery and Distribution of Ramapithecus G.E. Lewis in 1932 made the discovery of Ramapithecus for the first time ever in the Siwalik Hill region of India.