|
The Proboscidea of the Past
|
 (12-17-2015, 07:08 AM)tigerluver Wrote: To enter into the realm of a new group of giants, I invite you to Proboscidea with us. @tigerluver Great information, they were real Giants.
MAMMOTHS
 *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  *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  *This image is copyright of its original author  *This image is copyright of its original author  *This image is copyright of its original author
Palaeogenomes of Eurasian straight-tusked elephants challenge the current view of elephant evolution Meyer et al., 2017
 *This image is copyright of its original author A revised tree of phylogenetic relationships among elephantids, color-coded by their presumed geographical range. Abstract: "The straight-tusked elephants Palaeoloxodon spp. were widespread across Eurasia during the Pleistocene. Phylogenetic reconstructions using morphological traits have grouped them with Asian elephants (Elephas maximus), and many paleontologists place Palaeoloxodon within Elephas. Here, we report the recovery of full mitochondrial genomes from four and partial nuclear genomes from two P. antiquus fossils. These fossils were collected at two sites in Germany, Neumark-Nord and Weimar-Ehringsdorf, and likely date to interglacial periods ~120 and ~244 thousand years ago, respectively. Unexpectedly, nuclear and mitochondrial DNA analyses suggest that P. antiquus was a close relative of extant African forest elephants (Loxodonta cyclotis). Species previously referred to Palaeoloxodon are thus most parsimoniously explained as having diverged from the lineage of Loxodonta, indicating that Loxodonta has not been constrained to Africa. Our results demonstrate that the current picture of elephant evolution is in need of substantial revision." 
Maybe the entire Palaeoloxodon genus was convergently evolved toward Elephas?
BTW, the Palaeoloxodon species from India to China was likely the largest land mammal of all time, and they were playing the role of today's Asian elephants in the contemporary ecosystems.
Now we need to reclassify something as Palaeoloxodon and the African forest elephant are more closely related to each other.
Should the entire Palaeoloxodon genus be downgraded into a subgenus that belongs to Loxodonta or simply the African forest elephant moves to the genus of Palaeoloxodon?
Good question @GrizzlyClaws. I think that this situation is not completely clear and need more analysis and revisions.
From what i read, Palaeoloxodon is genetically closely related to Loxodonta cyclotis, but have many morphologically traits of Elephas maximus. I think that downgrad the genus Palaeoloxodon to a subgenus at the moment is the best way. This means that all three species are under the genus Loxodonta.
@Ngala
Should Loxodonta cyclotis also assign under the subgenus of Palaeoloxodon? BTW, there are also several different species under the subgenus Palaeoloxodon.
Now i read that the genus Loxodonta, in fact, is not considered valid. I tought that with the downgradation of the genus Palaeoloxodon described in 1920 to a subgenus, the genus Loxodonta (described before, in 1797) becomes valid, but i was wrong.
Read this interesting article @GrizzlyClaws: Elephant history rewritten by ancient genomes ..... "Love Dalén, a palaeogeneticist at the Swedish Museum of Natural History in Stockholm, says that the study will force a reshuffle of the elephant family tree. “Basically Loxodonta is not valid as a genus name,” he says. He thinks that taxonomists may need to come up with new names for the different species, to better represent the relationship between savannah, forest and straight-tusked elephants." ..... Furthermore, some species could be a results of interbreeding.
Maybe the African bush elephant could remain with the genus Loxodonta, while the African forest elephant has to move to the Palaeoloxodon one.
Notiomastodon platensis
 *This image is copyright of its original author  *This image is copyright of its original author  *This image is copyright of its original author Notiomastodon platensis is known from MECN 82, a 35-year-old male that would be approximately 2.52 metres (8.3 ft) tall, with an estimated weight of 4.4 tonnes (4.3 long tons; 4.9 short tons).It had two tusks on either side of its trunk, like other members of Gomphotheriidae. Unlike close relative Cuvieronius its tusks were not twisted, however their length and shape are observed as greatly variable depending on the individual. Here it is Notiomastodon based on a subadult fairly complete skeleton (some parts came from other individuals). Fully grown individuals may attained 2.9 m at the shoulders and more than 6 tonnes in body mass. Notiomastodon has been described as the 'lowland gomphothere'. The genus tended to inhabit seasonally dry, open forests, with a range lining most of the South American coastline and lowland interior, bar the Guiana Shield, with particularly large concentrations along the coast of Peru and in northeastern Brazil] The diet composition of Notiomastodon varied widely depending on location, but probably primarily consisted of a mix of C3 shrubs and C4 grasses, whilst also serving as a primary disperser of the seeds for a vareity of different plant species.
How a newly-discovered mastodon jaw became a mammoth mystery
Jeanne Timmons Wednesday 13 September 2017 14.49 BST Dr Chris Widga and his team thought the remains they were excavating were ‘just another mastodon’. But when the jaw appeared, it was unlike anything the team had ever seen. What exactly could it be? A section of the as yet unknown type of proboscidean jaw displaying distinctly mastodon teeth found at the Gray Fossil Site. Photograph: Charlie Warden/East Tennessee State University Photographic Services  *This image is copyright of its original author He’d been offering tantalising hints throughout his presentation: an ulna here; a large femur there; a calculated weight of 16 tons for this animal. But it wasn’t until he showed an image of the excavated jaw that some of us became really excited. This wasn’t a typical mastodon. And when someone like Dr Chris Widga – a palaeontologist with extensive proboscidean knowledge – looks at a fossil and isn’t sure what it is, it’s time to pay attention. Watching his presentation at the Valley of the Mastodons workshop, held early this August at the Western Science Center, California, my interest was certainly captured. The excavated jaw. Photograph: Charlie Warden_ETSU/Charlie Warden/East Tennessee State University Photographic Services  *This image is copyright of its original author While the woolly mammoth may dominate public imagination when it comes to ancient animals with trunks (or “proboscis”, hence the name “proboscideans”), there were numerous other similar species that evolved both before and alongside it. Mastodons (the genus Mammut) were relatively shorter and stockier than mammoths. Like mammoths, they had tusks, although theirs were less curvy. It is their teeth, however, that make them easily recognizable. Mastodon teeth actually look like teeth, whereas mammoth teeth resemble the footprints made by astronauts. A mammoth molar, left, and a footprint from Nasa’s Apollo 11 lunar mission. Photograph: Composite  *This image is copyright of its original author Until a year ago, Widga worked at the Illinois State Museum where he had access to a number of mastodon sites and collections in the surrounding states. He is now head curator at the Gray Fossil Site, an exciting Miocene site in Gray, Tennessee. The site itself was discovered in 2000, the happy result of a road project that was halted and moved after fossils were discovered. Thanks to local citizens, politicians and scientists, a museum literally stands atop the site. Because both site and museum are so new, there is no legacy data. In other words, researchers don’t have to devote time cataloguing information from fossils found within the past century; they’ve been able to digitize everything from day one. So far, they’ve catalogued 20,000 specimens, and the list keeps growing. Ancient rhino, alligator, invertebrates, plants and literally hundreds of tapirs have been found at the Gray Fossil Site. Mastodons, however, are less common thus far. And the excavation of this one particular proboscidean has been a slow process. A small tusk was discovered in 2000, but it wasn’t until 2015 that the rest of the animal began to be recovered. One of the mystery proboscidean’s feet. Photograph: Charlie Warden/East Tennessee State University Photographic Services  *This image is copyright of its original author “When I first saw the tooth,” said Widga, “I thought, ‘oh well, it’s just another mastodon.’ We would expect to see mastodons at that age [in the fossil record]. Not a big deal. “But when they started excavating the jaw and the skull, those were elements that looked very, very different. That’s when we realized this has the potential to be a very important specimen.” Again, it all goes back to that jaw. American mastodon (Mammut americanum) jaws are short in length. Some have small, thin chin tusks; others have no chin tusk at all. The Gray Fossil mastodon, in contrast, is markedly long with a much thicker chin tusk: two elements that do not indicate Mammut. It was this elongated jaw that prompted them to compare the fossil to another earlier proboscidean species – the gomphothere – which does have elongated jaws and which has been found in sites relatively close to Tennessee. The American mastodon has a short jaw, as seen in this specimen at the Beneski Museum, Amherst College. Photograph: Jeanne Timmons  *This image is copyright of its original author Gomphotheres evolved well before mastodons and mammoths, but they also eventually co-existed with them. They include species with four tusks, as well as species with a large flat tusk extending from the bottom lip, leading to the nickname “shovel-tuskers” (if you’ve seen the “Lord of the Rings” trilogy, you may notice that the elephants in that series bear a striking resemblance to gomphotheres). According to palaeontologist Michael Pasenko, who has spent much of his career studying that family, “[Gomphotheres] were way more diverse in North America than mastodons and mammoths. [They] are the only proboscideans that [we know] made it to [what is now known as] South America. Mammoths and mastodons never made it, but gomphotheres did.” But the Gray Fossil jaw doesn’t match those of gomphotheres, so it was ruled out. The next step? Looking further into mastodon ancestry to a species called Zygolophodon. Granted, I’m not an expert, but I’ve spent the past several years learning about proboscideans, and I’d never heard of Zygolophodon until the “Valley of the Mastodons” workshop. I connected with proboscidean paleontologist Rachel Silverstein for help understanding it. “I had a lot of trouble trying to understand what Zygolophodon WAS, let alone what its lineage was like,” she explained. “North American Zygolophodon teeth and Mammut americanum (American mastodon) teeth are nearly identical, so being able to separate the genera was important for my master’s thesis.” “I think the morphologic features of both genera are so similar,” she continued, “that paleontologists often overlook the possibility that what they find/describe could be Zygolophodon rather than Mammut. There’s just so little work done on Zygolophodon that making connections is difficult, especially since much of the large paleontological research on them is decades old.” Dr. Alton Dooley Jr. of the Western Science Center with a 14m-year-old Zygolophodon fossil from the Alf Museum. Photograph: Jeanne Timmons  *This image is copyright of its original author And yet the Gray Fossil jaw just doesn’t fit into this category either. “That’s part of the reason why we’re like, ‘ok it’s not completely like American mastodon, but yet it’s not completely like Zygolophodon,’” Dr. Widga stated. “It’s something in between. It exhibits characters of both of these taxa. We don’t think it’s a hybrid, but the exact relationship between Zygolophodon and Mammut is not well mapped right now.” It remains a mystery, then, at least while Widga and his team continue to excavate and prepare the bones for further analysis. So what do we know so far? “This mastodon shares characters with multiple fossil proboscideans. Ultimately, it belongs to the genus Mammut because of its teeth,” said Widga. “Mammut teeth were very conservative through time, in terms of their shape and size. But the rest of its skeleton is different. And given what we know from recent genetic studies of other elephants, there can be a lot of variability in the skeleton, and you can still end up with animals that can interbreed and be considered the same species, genetically. “I don’t know whether it will be a new species or not,” he concluded, “in part because we also need better definitions of the other species that are out there. What does Pliomastodon look like? What does early Mammut look like? What does Zygolophodon look like in North America? And once we tease that apart, then we’ll know better how the Gray Fossil Site mastodon fits into the bigger picture.”
cuvieronius hyodon
Cuvieronius is an extinct New World genus of gomphothere and is named after the French naturalist Georges Cuvier. Alive, species stood, on average, about 2.3 metres (7.5 ft) tall at the shoulder, weighed about 3.5 tonnes (3.4 long tons; 3.9 short tons) and would have superficially resembled modern elephants with spiral-shaped tusks. According to a group of Brazilian mammalogists, many sites in South America referred to Cuvieronius actually refer to Notiomastodon with many previous studies simply labeling fossils one or the other depending on location, with only localities definitely identified as Cuvieronius, the range now extends in the high Andes from Ecuador in the North, to Bolivia in the south, with the localities in the southern Andes in Chile and Argentina now thought to belong to Notiomastodon. The same group attains no confirmed fossils of Cuvieronius exist beyond 44,000 years ago in South America, so the species would not have been in South America at the time of human arrival. By the end of the Pleistocene, the northern limit of the range of Cuvieronius was in Mexico.  *This image is copyright of its original author  *This image is copyright of its original author
@Rishi probably you have heard that according new studies the largest land mammal specie ever to live on Earth is Paleoloxodon namadicus with estimated mass of 22 tons and the largest bone from this ancient elephant was found in India a 170 years ago by British researcher Prinsep (1834). Currently the femur of the giant must be stored SOMEWHERE in the museums of Calcutta.... Have you seen personally this gigantic femur in the open exposition and could you send us some photos of it? In this scientific article (Asier Larramendi, Shoulder height, body mass, and shape of proboscideans, page 559) are written following strange words:
"The distal femur portion of this specimen must be restudied. The fossils are LIKELY stored in the Indian Museum of Kolkata; until such a collection can be revised this size estimate will remain speculative." https://www.app.pan.pl/archive/published...362014.pdf ...I have an impression that nobody knows where exactly is stored this gigantic femur... If I am not wrong no current photos, only old descriptions. You understand the word is for mammal with size of dinosaur.. .You can see a paint of the animal in the very bottom of this article. @Polar do you know that in Paleontological museum of University of Sofia could be seen one of the largest if not the largest fully survived skeletons of Deinotherium giganteum in the world. The size of the skeleton is gigantic - 4 meters tall in the shoulders and 4,20 meters tall in the pelvis. I have seen numerous times this skeleton, its really enormous, was found in the aria of Ezerovo. Its body mass is estimated to be 13,2 tons (page 555-556): https://www.app.pan.pl/archive/published...362014.pdf But I think the body mass of that deinotherium is undersimated... Look, the largest African elephant ever with height of 3,96 meters in flesh weighted 12,24 tons. This deinotherium in flesh was 4,20 m tall in the shoulders and 4,40 m in the pelvis aria... and we know that deinotherium had more robust structure than African elephant... I suggest the real mass of that specimen should be 15-16 tons. What do you think? Image: http://photoplace.bg/photo/629496 |
| Users browsing this thread: |
| 4 Guest(s) |