Monkey skull. Comparison of the human skull with the skulls of anthropomorphic monkeys. Pictured is a gibbon ape
Working in Uganda, announced that it has found in the north of the country a primate skull about 20 million years old, the study of which could shed light on the history of the evolution of this region, reports France-Presse.
“This is the first time that paleontologists have managed to find a complete skull of a primate of this age. This is a very important find that will give Uganda more importance in the scientific world,” says Martin Pickford, a paleontologist at the College de France, France.
Found in volcanic rocks in the northeastern Karamoja region, the skull belonged to a male of the species Ugandapithecus Major, so named because the first remains of a large prehistoric ape of this hitherto unknown species were found in Uganda in 2000. These primates, distant relatives of modern great apes, lived in South Africa about 20 million years ago.
Initial analysis of the skull showed that the herbivorous, tree-climbing animal died at about 10 years of age, with a head the size of a chimpanzee and a brain volume similar to that of a baboon. The find will now be sent to Paris, France, for cleaning, x-raying and detailed description, after which it will return to Uganda again in about a year.
Let us recall that scientists have been searching in Africa for quite some time for an intermediate evolutionary link between Australopithecus africanus (A. africanus) and Homo habilis or Homo erectus. In 2010, one of the options was proposed by a team of paleoanthropologists led by Lee Berger from the University of the Witwatersrand in Johannesburg, South Africa: scientists presented a description of a new species of australopithecus, Australopithecus sediba, which can lay claim to the title of this very intermediate link .
Around the World previously reported that the remains of the prehistoric ape Darwinius masillae, identified in 2009 as a possible “missing link” between humans and primates, are actually akin to modern lemurs and lorises. Scientists have presented evidence that the 47-million-year-old Darwinius masillae is not a dry-nosed ape, which includes apes and humans, among others, but a member of the dry-nosed apes, a group of primates that includes lemurs and lorises.
Let us also recall that the scientific breakthrough of 2009 was the discovery of the fossilized skeleton of a human ancestor. The bones of a female Ardipithecus ramidus species that lived 4.4 million years ago were discovered in 1994, but due to the poor condition of the bones, researchers spent 15 years digging up the remains and analyzing them.
A study of the skull, teeth, pelvis, arm and leg bones showed that the creature, named Ardi, inherited a mixture of primitive traits from its ancestors and derived traits that were then passed on to later hominids, or humanoid creatures. Ardipithecus was even more primitive than the famous Lucy, a 3.2-million-year-old skeleton of a representative of Australopithecus.
There are distinctive features of the skull of modern humans, anthropomorphic apes and fossil hominids. This is, first of all, the predominance of the size of the cerebral part of the skull over the facial part in modern humans. One of the most important indicators is the capacity of the skull. Thus, the average capacity of the skull in a gorilla is 500 cm3, in Zinjanthropus - 530 cm3, in Australopithecus - 435-520 cm3, in Homo habilis - 657-680 cm3, in Pithecanthropus - 900 cm3, in Sinanthropus - 915-1225 cm3, in Neanderthal - 1325 cm3, in Cro-Magnon man - 1400-1600 cm3, in modern man - 1400 cm3. In humans, the upper part of the squama of the occipital bone grows, and the position of the foramen magnum changes, moving anteriorly and downward, which is one of the most important differences between the human skull and skulls of apes. The mastoid process in modern humans is well defined, but is almost absent in apes. The development of the mastoid process is associated with the function of the sternocleidomastoid muscle, which is attached to it. In contrast to the sloping forehead of ancient hominids and apes, the forehead of modern humans is convex, and the slope of the scales of the frontal bone is small. The angle, the apex of which is the glabella (inion-glabella-bregma), in modern humans is no less than 56-61?, in Pithecanthropus it is 37-38?, in Neanderthals - 44-53?. The angle of curvature of the base of the skull, connecting three points - the bazion, the point on the posterior edge of the pre-cross groove and the nasion, in modern humans is 131-135?, in a gorilla - 178?, in chimpanzees - 159?. The ratio of the mass of the lower jaw to the mass of the skull (without the lower jaw) in a gorilla is 40-46%, in humans - 15%. In apes, the angle between the body of the lower jaw and its branch is about 90?, on the fossil Heidelberg jaw it is slightly larger - 95?, in Neanderthals it increases to 100?, in humans it is 110-130?. The jaws of anthropomorphic monkeys, unlike those of humans, protrude sharply; this feature is preserved in Pithecanthropus and Sinanthropus.Dedicated to the results of a comprehensive study of the bones of Ardipithecus, a bipedal monkey that lived in northeastern Ethiopia 4.4 million years ago. New data allow us to confidently interpret Ardipithecus as a transitional link between the common ancestor of humans and chimpanzees (who lived about 7 million years ago) and Australopithecus, which appeared about 4 million years ago. Ardipithecus lived in wooded areas (but not in impenetrable forests), was an omnivore and moved along branches on all fours, leaning on the palms of his hands, and on the ground on two legs. The lack of sexual dimorphism and small canines may indicate reduced intragroup aggression. A study has found that our ancestors were much less similar to chimpanzees than previously thought.
View Ardipithecus ramidus was described in 1994 from several teeth and jaw fragments. In subsequent years, the collection of bone remains of Ardipithecus was significantly expanded and now includes 109 specimens. The biggest success was the discovery of a significant part of the skeleton of a female individual, which scientists solemnly presented to journalists under the name Ardi at a press conference on October 1, 2009.
Eleven large articles published in a special issue of the journal Science, sum up the results of many years of work by a large international research team. The publication of these articles and their main character, Ardi, were widely publicized in the media. And this is by no means empty hype, because the study of the bones of Ardipithecus actually made it possible to reconstruct the early stages of hominin evolution in much more detail and accurately.
As previously assumed based on the study of the first fragmentary finds, A. ramidus is a transitional link between the common ancestor of humans and chimpanzees (Orrorin and Sahelanthropus were apparently close to this ancestor) and later representatives of hominins - Australopithecines, from which, in turn, the first people descended ( Homo).
Until now, the oldest hominin species studied in detail was Australopithecus afarensis (about 3.0-3.7 million years ago) (see: Donald Johanson, Maitland Eady. “Lucy: the origins of the human race”; “Daughter Lucy” walked like a person, but climbed trees and thought like a monkey, “Elements”, 09/26/2006). All more ancient species known to science (in order of increasing antiquity: Australopithecus anamensis, Ardipithecus ramidus, Ardipithecus kadabba, Orrorin tugenensis, Sahelanthropus chadensis), were studied on the basis of fragmentary material. Accordingly, our knowledge about their structure, lifestyle and evolution also remained fragmentary and inaccurate. And now the honorary title of “the oldest well-studied hominin” has solemnly passed from Lucy to Ardi.
1. Dating and features of the burial. Bones A. ramidus come from a single layer of sediment about 3 m thick, sandwiched between two volcanic layers. The age of these layers was reliably established using the argon-argon method and turned out to be the same (within the measurement error) - 4.4 million years. This means that the bone-bearing layer was formed (as a result of floods) relatively quickly - a maximum of 100,000 years, but most likely - over several millennia or even centuries.
Excavations began in 1981. To date, more than 140,000 specimens of vertebrate bones have been obtained, of which 6,000 are family-identifiable. Among them are 109 samples A. ramidus, belonging to at least 36 individuals. Fragments of Ardi's skeleton were scattered over an area of about 3 square meters. m. The bones were unusually fragile, so extracting them from the rock took a lot of work. Ardi's cause of death has not been established. She was not eaten by predators, but her remains, apparently, were thoroughly trampled by large herbivores. The skull was especially damaged, as it was crushed into many fragments scattered over a large area.
2. Environment. Along with the bones A. ramidus Remains of various animals and plants were found. Forest plants predominate among plants, and animals that feed on leaves or fruits of trees (rather than grass) predominate. Judging by these finds, Ardipithecus did not live in the savannah, but in wooded areas, where areas of dense forest alternated with more sparse ones. The ratio of carbon isotopes 12 C and 13 C in the tooth enamel of five individuals A. ramidus indicates that Ardipithecus fed mainly on forest products rather than savannah (savannah grasses are characterized by a low content of the 13 C isotope, see: Isotopic signature). In this, Ardipithecus differs sharply from its descendants - Australopithecus, which received from 30 to 80% of carbon from open space ecosystems (Ardipithecus - from 10 to 25%). However, Ardipithecus were still not purely forest dwellers, like chimpanzees, whose food is almost 100% of forest origin.
The fact that Ardipithecus lived in the forest contradicts the hypothesis that the early stages of hominin evolution and the development of bipedal walking were associated with the emergence of our ancestors from the forest to the savannah. Similar conclusions were previously drawn from studies of Orrorin and Sahelanthropus, which also apparently walked on two legs but lived in wooded areas.
3. Skull and teeth. Ardi's skull is very similar to that of Sahelanthropus. In particular, both species are characterized by a small brain volume (300-350 cc), a foramen magnum displaced forward (that is, the spine was attached to the skull not from behind, but from below, which indicates bipedal walking), and also less developed than in chimpanzees and gorillas, molars and premolars. Apparently, pronounced prognathism (protrusion of the jaws forward) in modern African apes is not a primitive trait and developed in them after their ancestors separated from the ancestors of humans.
Ardipithecus teeth are the teeth of an omnivore. The entire set of characteristics (the size of the teeth, their shape, the thickness of the enamel, the nature of microscopic scratches on the tooth surface, etc.) indicates that Ardipithecus did not specialize on any one diet - for example, on fruits, like chimpanzees, or leaves, like gorilla. Apparently, Ardipithecus fed both in trees and on the ground, and their food was not too tough.
One of the most important facts established by researchers is that in males A. ramidus, unlike modern apes, the fangs were no larger than those of females. Male monkeys actively use their fangs both to intimidate rivals and as a weapon. The most ancient hominins ( Ardipithecus kadabba, Orrorin, Sahelanthropus) the fangs of males and females, if they differed in size and shape, then only slightly; Subsequently, in the “human” evolutionary line, these differences finally disappeared (the “feminization of the fangs” occurred), and in chimpanzees and gorillas they intensified a second time. The pygmy chimpanzee (bonobo) has less sexual dimorphism in canine size than other living apes. Bonobos are also characterized by the lowest level of intraspecific aggression. The authors believe that there may be a direct connection between the size of canine teeth in males and intraspecific aggression. In other words, it can be assumed that the decrease in canines in our distant ancestors was associated with certain changes in the social structure, for example, with a decrease in conflicts between males.
4. Body size. Ardi's height was approximately 120 cm, weight - about 50 kg. Males and females of Ardipithecus were almost the same in size. Extremely weak sexual dimorphism in body size is also characteristic of modern chimpanzees and bonobos, with their relatively equal relationships between the sexes. In gorillas, on the contrary, dimorphism is very pronounced, which is usually associated with polygamy and the harem system (see: Paranthropus had harems, “Elements”, 12/04/2007). In the descendants of Ardipithecus - Australopithecus - sexual dimorphism increased, although this was not necessarily associated with the dominance of males over females and the establishment of a harem system. The authors admit that males may have grown larger and females may have shrunk due to their move to the savannah, where males had to take over protecting the group from predators, and females may have learned to cooperate better with each other, which made physical power less important to them .
5. Postcranial skeleton. Ardie walked on the ground on two legs, although less confidently than Lucy and her relatives, the Australopithecus. At the same time, Ardi has retained many specific adaptations for effective tree climbing. In accordance with this, in the structure of Ardi’s pelvis and legs there is a combination of primitive (“monkey”, oriented towards climbing) and advanced (“human”, oriented towards walking) features.
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Ardi's hands are exceptionally well preserved (unlike Lucy's hands). Their study allowed us to draw important evolutionary conclusions. Until now, it was generally accepted that human ancestors, like chimpanzees and gorillas, walked by leaning on their knuckles. This peculiar method of movement is characteristic only of African apes; other monkeys lean on their palms when walking. However, Ardi's hands lack the specific features associated with knuckle-walking. The hand of Ardipithecus is generally more flexible and mobile than that of chimpanzees and gorillas, and in a number of ways is similar to humans. It is now clear that these characteristics are “primitive”, original to hominins (and, apparently, to the common ancestor of humans and chimpanzees). The structure of the hand that is characteristic of chimpanzees and gorillas (which, incidentally, does not allow them to manipulate objects as deftly as we do) is, on the contrary, advanced and specialized. The strong, prehensile hands of chimpanzees and gorillas allow these massive animals to move efficiently through trees, but are poorly suited for fine manipulation. The hands of Ardipithecus allowed him to walk along the branches, leaning on his palms, and were better suited for tool work. Therefore, in the course of further evolution, our ancestors did not have to “remake” their hands that much.
Ardipithecus presented anthropologists with many surprises. According to the authors, no one could have predicted such a mosaic of primitive and advanced features, which was found in Ardipithecus, without having real paleoanthropological material in hand. For example, it never occurred to anyone that our ancestors at first adapted to walk on two legs due to transformations of the pelvis, and only after abandoned the opposable thumb and the grasping function of the feet.
The study showed that some popular hypotheses about the paths and mechanisms of hominin evolution need to be revised. Many of the features characteristic of modern apes turned out to be not primitive (as was thought), but advanced, specific features of chimpanzees and gorillas, associated with deep specialization for climbing trees, hanging on branches, “knuckle walking,” and a specific diet. Our common ancestors did not have these characteristics. Those monkeys from which man descended were not very similar to those of today.
Most likely, this applies not only to the physical structure, but also to the behavior of our ancestors. Perhaps the thinking and social relationships of chimpanzees is not such a good model for reconstructing the thinking and social relationships of our distant ancestors. In the final article of the special issue Science Owen Lovejoy calls for abandoning the conventional wisdom that Australopithecines were something like chimpanzees that learned to walk upright. Lovejoy emphasizes that in reality, chimpanzees and gorillas are extremely unique, specialized, relict primates, hiding in impenetrable tropical forests and that is why they have survived to this day. Based on new facts, Lovejoy developed an original and very interesting model of the early evolution of hominins, which we will discuss in a separate note.
Man descended from the monkey. This postulate, known since the time of Darwin, is constantly being challenged, but science every time finds new evidence that chimpanzees, gibbons and gorillas are indeed close relatives of humans. This is evidenced by archaeological finds and DNA studies, which show amazing coincidences in the genetic code. But nevertheless, scientists do not yet have a complete idea of how the common ancestors of monkeys and humans lived and looked. A 13-million-year-old complete child's skull of an ancient ape, recently discovered in Kenya, may lift the veil of this mystery.
Distant relatives
Among living primates, humans are most closely related to apes, including chimpanzees, gorillas, orangutans and gibbons. Our common ancestor with chimpanzees lived in Africa 6-7 million years ago, and archaeologists have found much evidence of how humans have evolved since then. However, very little is known about the evolution of the common ancestors of apes and humans before 10 million years ago. Usually, from that time on, a few teeth or pieces of jaw can be found. Therefore, two main questions remained unanswered: did the ancestor of people and monkeys live in Africa and what was he like?
The skull that will help scientists answer these questions was found in an ancient layer of rock in the Napudet region, west of Lake Turkana in northern Kenya. 13 million years ago, a nearby volcano buried under a layer of lava and ash the forest in which this baby lived, as well as countless trees that are of great scientific interest today.
Alesi's story
Modern scanning technologies have made it possible to closely examine the cranial cavity, inner ears and ungrown “adult” teeth. Based on the teeth, it was possible to establish that the baby, who received the name Alesi, was only 1 year and 4 months old at the time of death. It belongs to a new species called Nyanzapithecus alesi.
Until now, only teeth were found in different species of Nyanzapithecus, which did not even allow us to say whether they belong to primates. Scientists are now confident that Nyanzapithecus alesi is the ancestor of living apes and humans.
Alesi's lemon-sized skull resembles that of a baby gibbon. However, it cannot be said that they are direct relatives of gibbons: the ancient monkey had much in common with other modern species. In addition, gibbons show miracles of balancing act and acrobatics, swinging on branches. Alesi's relatives are unlikely to have had the same abilities: the structure of the inner ear suggests that the vestibular apparatus of Nyanzapithecus alesi was not adapted for this.
The main thing that the Kenyan find says is that the species found was part of a group of primates that existed in Africa more than 10 million years ago. This group was related to the origins of modern apes and humans, and these origins were definitely African.
The skull is a symbol of knowledge or a valuable thing that you do not know how to use. Historical figure or powerful rival.
Finding a skull means finding a trail, coming across an important idea.
To dig a skull out of the ground means to look for answers to something important in the past.
Burying the skull means eliminating what contributed to the delusion.
Keeping a skull on your table means receiving help in spiritual work.
A collection of skulls means significant connections, interesting friends.
The skull is framed in gold - a meeting with a scientist or getting to know him.
A skull in the form of a bowl or drinking from it - immerse yourself in the world of religious ideas, fruitful ideas in general.
Pouring water from a skull means striving for a moral ideal.
To pour water from it onto the ground means to lose spiritual strength.
Scooping a skull from a river means finding fruitful ideas in a fantasy world.
To store money in the skull means to receive benefits from spiritual figures.
Breaking a skull with a hammer means ruin, deception.
Wearing a skull on a pole means setting out on a journey for the wrong purpose.
To pray to a skull is to overestimate the role of the mind in life, to create an idol for yourself out of a certain person.
Kissing a skull means longing for the dead.
Throwing out the skull means trying in vain to start a new life. To abandon good principles, to forget the deceased undeservedly.
Boil water in the skull - give in to crazy ideas, waste great things on trifles.
To see a giant skull is to have a false judgment of authority.
A skull that is too small means underestimating the capabilities of your mind.
Skull with three eyes - indicates a great person in your environment, a magician, etc.
The metal skull is an evil person.
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