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Extinct Ancestors of Modern Animals
Extinct Ancestors of Modern Animals
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Extinct Ancestors of Modern Animals
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http://thechive.com/2015/01/18/animals-w...st-photos/
 *This image is copyright of its original author Check out all the animals and images from the link posted. 
Nice find, but the first picture, that of Dienosuchus and T-rex is rather misleading. Mature individuals were basically the same length, roughly 40 feet long. The alligator was probably heavier though. Such an encounter was likely common and the outcome would be really interesting.
(01-22-2015, 07:38 PM)'brotherbear' Wrote: Nice find, but the first picture, that of Dienosuchus and T-rex is rather misleading. Mature individuals were basically the same length, roughly 40 feet long. The alligator was probably heavier though. Such an encounter was likely common and the outcome would be really interesting. I am sure it is, I just figured it would be interesting to review. 
Recently, I had to report on whales to do. Here's the evolutionary tree:
 *This image is copyright of its original author  *This image is copyright of its original author I like the thread topic. We should find evolutionary trees for different species and allocate them here for ease of access of our users.
Birds, courtesy of U. Berkeley.
 *This image is copyright of its original author
https://archaeologynewsnetwork.blogspot....Wcrz3sY.97
Frankfurt am Main, Germany, June 11th, 2014. According to researchers of the LOEWE Biodiversity and Climate Research Centre (BiK-F), Goethe University Frankfurt and the U.S. Wildlife Service several bear species that today only occur in America or in Asia have hybridized in their evolutionary history. The Beringia land bridge, which in former times connected the habitats of these species, might have enabled their encounter. The large-scale study is based on the comparison and analysis of genetic material of all bear species that still exist. The results have been published recently in the journal Evolution and Molecular Biology. Read more at https://archaeologynewsnetwork.blogspot....OlpZXsG.99 If in documentaries or in the zoo - everyone has seen and knows about brown bears, polar bears and pandas. However, there are several other bear species in Asia and South America that are less well-known, such as the sloth bear, the Asiatic or the spectacled bear. There are eight bear species that still exist worldwide. Despite many years of research, the exact relationships between them remain unresolved. Who with whom? Polar bear and brown have hybridized Previous analyses of genetic material of polar bears and brown bears have proven already that the two species have hybridized during their long evolutionary history. This behavior can still be observed today and the ongoing climate change drives the bear even closer. It is therefore likely that there have been similar exchanges of genetic material between other species of the bear family. ... as well as brown bears and black bears To shed light on this, a team of the German Biodiversity and Climate Research Centre (BiK-F) and the Goethe University Frankfurt in cooperation with colleagues from the US have now analyzed certain genome parts of all bear species alive today. Read more at https://archaeologynewsnetwork.blogspot....OlpZXsG.99 "We were able to show that several bear species have hybridized during their evolutionary history. The exchange can still be traced in the genetic makeup of today's bears," says the lead author of the study, Verena Kutschera (BiK-F). This mix-up makes it difficult to classify some gene fragments as belonging to a particular species. Beringia land bridge serving as an intercontinental meeting point Surprisingly, several bear species which nowadays live on different continents have also taken part in the mating and thus gene exchange. This may have been possible because the significantly lower sea level during past ice ages resulted in a land bridge between Asia and North America, the Beringia land bridge. Thus the ancestors of today’s bear species, e.g. of the Asiatic black bear and the American black bear, had the opportunity to meet and to mate. Darwin’s species tree is insufficient to map complicated relationships All eight bear species that occur today have well adapted to their present habi-tat and differ physically very much. A prime example for this is polar bears and black bears. Nevertheless, the speciation of some individual genes has not finished yet which additionally complicates the research of the evolution of bears. With new molecular methods more gene parts might be discovered in the genomes of mammal species that could originate from other species. Apparently separate genetic lineages turn out to have merged – sometimes repeatedly – during the evolutionary history and exchanged genetic material with each other. Read more at https://archaeologynewsnetwork.blogspot....OlpZXsG.99 "The traditional pedigree already used by Darwin is not always suitable to map evolutionary history in full detail. So-called phylogenetic networks a more useful to depict the genetic mix-up that we have found ", comments evolutionary biologist Prof. Dr. Axel Janke, BiK-F, leader of the research team. The study demonstrates that evolution often is not a linear process; thanks to modern molecular methods it’s complex processes are finally revealed. Source: Senckenberg Research Institute and Natural History Museum [June 12, 2014] Read more at https://archaeologynewsnetwork.blogspot....OlpZXsG.99  *This image is copyright of its original author
Here is an ancestor of our modern seals, sea lions, and walrus. This makes me wonder if, given that the polar bear survives climate change and human activity, would the polar bear eventually evolve into a more aquatic predator? The 'family tree' of Carnivora places the seals, sea lions, and walrus as being closely related to bears.
https://blogs.scientificamerican.com/new...009-04-22/  *This image is copyright of its original author
50 Million Years of Horse Evolution
 *This image is copyright of its original author The Evolution of Horses, from Eohippus to the American Zebra Apart from a couple of bothersome side branches, horse evolution presents a neat, orderly picture of natural selection in action. The basic story line goes like this: as the woodlands of North America gave way to grassy plains, the tiny proto-horses of the Eocene epoch (about 50 million years ago) gradually evolved single, large toes on their feet, more sophisticated teeth, larger sizes and the ability to run at a clip, culminating in the modern horse genus Equus. This story has the virtue of being essentially true, with a couple of important “ands” and “buts.” But before we embark on this journey, it’s important to dial back a bit and place horses in their proper position on the evolutionary tree of life. Technically, horses are “perissodactyls,” that is, ungulates (hoofed mammals) with odd numbers of toes. The other main branch of hoofed mammals, the even-toed “artiodactyls,” are represented today by pigs, deer, sheep, goats and cattle, whereas the only other significant perissodactyls beside horses are tapirs and rhinoceroses. What this means is that perissodactyls and artiodactyls (which counted among the mammalian megafauna of prehistoric times) both evolved from a common ancestor, which lived only a few million years after the demise of the dinosaurs at the end of the Cretaceous period, 65 million years ago. In fact, the earliest perissodactyls (like Eohiippus, the ancestor of all horses) looked more like small deer than majestic equines! The Earliest Horses – Hyracotherium and Mesohippus Until an even earlier candidate is found, paleontologists agree that the ultimate ancestor of all modern horses was Eohippus, the “dawn horse,” a tiny (no more than 50 pounds), deer-like herbivore with four toes on its front feet and three toes on its back feet. (Eohippus was for many years known as Hyracotherium, a subtle paleontological difference of which the less you know, the better!) The giveaway to Eohippus’ status is its posture: this perissodactyl put most of its weight on a single toe of each foot, anticipating later equine developments. Eohippus was closely related to another early ungulate, Palaeotherium, which occupied a distant side branch of the horse evolutionary tree. Five to ten million years after Hyracotherium came Orohippus (“mountain horse”), Mesohippus (“middle horse”), and Miohippus (“Miocene horse,” even though it went extinct long before the Miocene epoch). These perissodactyls were about the size of large dogs, and sported slightly longer limbs with enhanced middle toes on each foot. They probably spent most of their time in dense woodlands, but may have ventured out onto the grassy plains for short jaunts. As horses evolved, they increased in size and lost all but one of their toes  *This image is copyright of its original author Toward True Horses – Epihippus, Parahippus and Merychippus During the Miocene epoch, North America saw the evolution of “intermediate” horses, bigger than Hyracotherium and its ilk but smaller than the equines that followed. One of the most important of these was Epihippus (“marginal horse”), which was slightly heavier (possibly weighing a few hundred pounds) and equipped with more robust grinding teeth than its ancestors. As you might have guessed, Epihippus also continued the trend toward enlarged middle toes, and it seems to have been the first prehistoric horse to spend more time feeding in meadows than in forests. Following Epihippus were two more “hippi,” Parahippus and Merychippus. Parahippus (“almost horse”) can be considered a next-model Miohippus, slightly bigger than its ancestor and (like Epihippus) sporting long legs, robust teeth, and enlarged middle toes. Merychippus (“ruminant horse”) was the largest of all these intermediate equines, about the size of a modern horse (1,000 pounds) and blessed with an especially fast gait. Next Step, Equus – Hipparion and Hippidion Following the success of intermediate horses like Parahippus and Merychippus, the stage was set for the emergence of bigger, more robust, more “horsey” horses. Chief among these were the similarly named Hipparion (“like a horse”) and Hippidion (“like a pony”). Hipparion was the most successful horse of its day, radiating out from its North American habitat (by way of the Siberian land bridge) to Africa and Eurasia. Hipparion was about the size of a modern horse; only a trained eye would have noticed the two vestigial toes surrounding its single hooves. Lesser known than Hipparion, but perhaps more interesting, was Hippidion, one of the few prehistoric horses to have colonized South America (where it persisted until historical times). The donkey-sized Hippidion was distinguished by its prominent nasal bones, a clue that it had a highly developed sense of smell. Hippidion may well turn out to have been a species of Equus, making it more closely related to modern horses than Hipparion was. Speaking of Equus, this genus–which includes modern horses, zebras and donkeys–evolved in North America during the Pliocene epoch, about four million years ago, and then, like Hipparion, migrated across the land bridge to Eurasia. The last Ice Age saw the extinction of both North and South American horses, which disappeared from both continents by about 10,000 B.C. Ironically, though, Equus continued to flourish on the plains of Eurasia, and was reintroduced to the Americas by the European colonizing expeditions of the 15th and 16th centuries A.D. Here’s a list of the most notable prehistoric horses American Zebra Also known as the Hagerman horse. Anchitherium A long-lived “side branch” on the equine tree of life. Dinohippus This prehistoric horse wasn’t quite as fearsome as its name. Epihippus This tiny, prehistoric horse lived about 30 million years ago. Eurohippus Scientists have discovered a pregnant specimen of this ancient horse. Hipparion One of the most successful horses of the Miocene epoch. Hippidion This donkey-sized horse had a prominent snout. Hypohippus This Miocene horse had unusually short legs. Hyracotherium The horse formerly known as Eohippus. Merychippus An important intermediate step in equine evolution. Mesohippus This “middle horse” was about the size of a deer. Miohippus This “Miocene horse” actually lived much earlier. Orohippus This prehistoric horse was a close relative of Hyracotherium. Palaeotherium This tapir-like beast was remotely related to modern horses. Parahippus This “almost horse” had noticeably enlarged middle toes. Pliohippus This prehistoric horse was built for speed. Quagga This South African zebra went extinct in 1883. Tarpan The immediate predecessor of the modern horse. 
Prehistoric Pecari Platygonus compressus
 *This image is copyright of its original author  *This image is copyright of its original author  *This image is copyright of its original author Platygonus compressus was a lot larger than all present day Pecaries with a height at the shoulders of 76 centimeters and estimated weight of 70 kilograms, it looked a lot like present day Pecaries, picture number 3 is of modern day Pecari to compare them.
Giant Prehistoric Capibara Noechoerus
 *This image is copyright of its original author  *This image is copyright of its original author  *This image is copyright of its original author  *This image is copyright of its original author Noechoerus was a very large Capibara 30% larger than present day Capibara with a head and body length of 1,70 mt and estimated weigth of 150 kilograms. Present day Capibaras have a head and body length up to 1,36 mt and maximum weight of 65 kilograms. Last picture down is a modern day Capibara to compare them. Information from Book BESTIAS PREHISTORICAS DE VENEZUELA (Jorge Domingo Carrillo Briceño)
Phoberomys pattersoni
 *This image is copyright of its original author Phoberomys pattersoni was a giant prehistoric rodent found in Venezuela in 2000 in the Urumaco Formation, it was reported by Sanchez-Villagra, Aguilera, and Horowitz in 2003. With the discovery of an almost complete skeleton it was possible to estimate its size and body mass, head and body length of 9 feet long (2,70 mt) and weighted 700 pounds (318 kilograms) with a height at the shoulders of 4,2 feet (1,28 mt). Book Urumaco and Venezuelan Paleontology, Restoration of Phoberomys pattersoni Artwork by Jorge Gonzalez. 
Incredible, the giant rodents in the past have made the largest felines absolutely irrelevant.
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