The Proboscidea of the Past - Printable Version

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The Proboscidea of the Past - tigerluver - 12-17-2015

To enter into the realm of a new group of giants, I invite you to Proboscidea with us.

Shoulder height, body mass and shape of proboscideans by Asier Larramendi is a groundbreaking publication is still in press, but has been released in its pre-official form. A few aspects are special about this work. One, the authors reconstruct an entire animal, rather than just mass. Two, the authors have used new methods based on volume to mass relationships rather than basic isometry, using equations as complex as those used to estimates masses of dinosaurs. Three, they provided visual comparisons, what better way to start this topic?

*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

Palaeoloxodon namadicus is the final major finding of this study, considering the proposal of its size. If accurate, a new king of mammals may have just been crowned.

My own interest in this order was piqued by the Javan specimens. More on that next. Until then, share as much you'd like!

RE: The Proboscidea of the Past - GrizzlyClaws - 12-17-2015

Palaeoloxodon was closely related to Elephas, and they did coexist in many millennia from India to China.

Eventually, Palaeoloxodon was outcompeted and fully displaced by Elephas.

RE: The Proboscidea of the Past - GrizzlyClaws - 12-17-2015

Here is a complete Palaeoloxodon namadicus specimen from China, and it was previously mistaken as the Mammuthus Sungari, a junior subspecies of Mammuthus trogontherii that lived in China in the late Pleistocene.

*This image is copyright of its original author

RE: The Proboscidea of the Past - GuateGojira - 12-17-2015

Wow, this is amazing. Those comparison images are the one I love, see the size of those magnificent ancient giants.

The Palaeoloxodon namadicus seems to be the new true giant, but like the giant dinosaurs, they are known only from few bones. At least, in this case, we have modern elephants and complete-semi complete mammoths and mastodons that can help us to get an accurate idea about how these giants were.

I have other document from Dr Christiansen (2004) about the body mass of the Proboscidean (attached document), so we can compare the results.

By the way, check this relative old table (source included) about the estimated shoulder height of some of those large animals:

*This image is copyright of its original author

RE: The Proboscidea of the Past - brotherbear - 12-18-2015

How does Palaeoloxodon namadicus stack up against the Songhua River mammoth ? It appears to be a close race for biggest-ever terrestrial mammal. 
Now I am reading that perhaps Mammuthus sungari was not a distinct species at all:  http://eofauna.com/en/investigacion/songhua-river-mammoths

RE: The Proboscidea of the Past - tigerluver - 12-28-2015

Stegodons of Sunda

Pleistocene Sunda was home to the small to medium size Stegodons, with size evolving dramatically with time. The Late Neogene elephantoid-bearing faunas of Indonesia and their palaeozoogeographic implications by Gert D. van den Bergh examines these species and give us body mass estimates.

He used 4 equations to estimate body mass:
1) Mass (kg) = 3.790 × 10-4 × FC (mm)2.827 (5.5 mm < FC < 413 mm)
2) Mass (kg) = 9.448 × 10-4 × HC (mm)2.611 (4.9 mm < HC < 459 mm) 
3) Mass (kg) = 1.774 × 10-5 × FL (mm)2.654 (6.0 mm < FL < 980 mm) 
4) Mass (kg) = 2.767 × 10-5 × HL (mm)2.675 (5.7 mm < HL < 830 mm) 

The specimens:

S. sondaari of Flores, Indonesia:
A fragmentary femoral piece with missing the proximal extremity. Bone length was estimated but circumference was able to be measured. The length equation produced an estimate of 207 kg and the circumference equation an estimate of 553 kg.

S. sompoensis of Sompe, Indonesia:
A single complete humerus. Estimated to be 350 kg on length and 950 kg on circumference.

S. t. trigonocephalus from Trinil HK and Kedung Brubus, Java:
Four femurs were examined, but there were two largest specimen candidates. The largest femoral length estimate was 1713 kg and said to be the second largest specimen, but the circumference estimate for this femur was not given in the text, and I can't find the supplementary tables yet. The largest specimen was fragmentary, but the circumference estimate gave an estimate of 6287 kg.

S. florensis of Flores, Indonesia:
A single humerus taken from Hooijer (1972) measuring 630 cm in length, producing an estimate of 852 kg. This fossil is lost, thus circumference could not be taken. Another fragmentary humerus of circumference c. 280 mm was estimated at 2317 kg. 

All specimens are said to be adults.

The author stated that the length estimates were probably more accurate while the circumference estimates were too high, citing that increase in bone width may be due to gait and not weight bearing. I subsequently tested the aforementioned equation on two elephants from Campione and Evans (2012) and found the following percent errors (+ indicates overestimate, - underestimate).

Asian elephant:
Humerus Length: -50%
Humerus Circumference: -15%
Femur Length: -56%
Femur Circumference: +24%

African elephant:
Humerus Length: -50%
Humerus Circumference: +1.4%
Femur Length: -64%
Femur Circumference: +33%

As we can see, the length based estimates are extreme underestimates. Femur circumference is a significant over estimate, thus correcting the estimates by around mass/1.25 may provide the most accurate estimate on its own. Humerus circumference are probably accurate enough. 

Thus, from the Sunda stegodons, the largest specimen,  of S. t. trigonocephalus, would weight around 5030 kg, around the size of an Asian elephant. Although, these stegodons were much more robust (we see this trend in the tiger of the area as well, go figure), and likely shorter even though the masses were similar.

S. t. ngandongensis of Ngandong may have been somewhat larger than S. t. trigonocephalus based on its larger dentition, but dentitions are very inconclusive.

RE: Extinct Animal News (Except Dinosaurs) - Ngala - 04-08-2016

The effect of area and isolation on insular dwarf proboscideans Van der Geer et al., 2016

*This image is copyright of its original author

Figure 1.  Reconstruction of four insular dwarf proboscideans with their respective mainland ancestors. Mainland proboscideans: 1, Palaeoloxodon antiquus; 2, Mammuthus columbi; 3, Stegodon zdanskyi. Insular proboscideans: 4, Palaeoloxodon ‘mnaidriensis’; 5, Palaeoloxodon falconeri; 6, Mammuthus exilis; 7, Stegodon aurorae
Based on skeletons at Museo di Paleontología, University of Rome, Italy (1), American Museum of Natural History, New York (2), Taylor Made Fossils, U.S. (3), Museo di Paleontología e Geología G.G. Gemmellaro, Palermo, Italy (4), Forschungsinstitut und Naturmuseum Senckenberg, Frankfurt, Germany (5), Santa Barbara Museum of Natural History, Santa Barbara, U.S. (6), Taga Town Museum, Honshu, Japan (7).
Photo and information credits: Van der Geer et al.

Aim: We investigated the hypothesis that insular body size of fossil elephants is directly related to isolation and surface area of the focal islands.
Location: Palaeo-islands worldwide.
Methods: We assembled data on the geographical characteristics (area and isolation) of islands and body size evolution of palaeo-insular species for 22 insular species of fossil elephants across 17 islands.
Results: Our results support the generality of the island rule in the sense that all but one of the elephants experienced dwarfism on islands. The smallest islands generally harbour the smallest elephants. We found no support for the hypothesis that body size of elephants declines with island isolation. Body size is weakly and positively correlated with island area for proboscideans as a whole, but more strongly correlated for Stegodontidae when considered separately. Average body size decrease is much higher when competitors are present.

Main conclusions
Body size in insular elephants is not significantly correlated with the isolation of an island. Surface area, however, is a significant predictor of body size. The correlation is positive but relatively weak; c. 23% of the variation is explained by surface area. Body size variation seems most strongly influenced by ecological interactions with competitors, possibly followed by time in isolation. Elephants exhibited far more extreme cases of dwarfism than extant insular mammals, which is consistent with the substantially more extended period of deep geological time that the selective pressures could act on these insular populations.

This study provides further support for the applicability of the island rule to the largest terrestrial mammalian herbivorous taxa (see Benton et al., 2010 and Stein et al., 2010 for intriguing indications that very large herbivorous dinosaurs such as titanosaurian sauropods may have also followed the predicted pattern).
The patterns discussed here for body size variation in proboscideans over space and time do not support a significant relationship between isolation and body size decrease for proboscideans. Islands relatively close to the mainland may harbour extremely size-reduced proboscideans as well as normal-sized species. Islands further away than 48 km (the maximum reported distance an Asian elephant can swim) do not harbour the smallest species.
The correlation between area and body size is positive but weak with much scatter around the trend for all proboscideans, but more robust for Stegodon from low latitude islands. Our observations support an ecological hypothesis of body size evolution, inferred from the significant influence of competition on body size evolution (see also Palombo, 2009). On the mainland and on relatively balanced and ecologically rich palaeo-islands such as Sulawesi, interaction with ecologically relevant species resulted in a (relatively) large body size. On islands with more depauperate assemblages, however, release from these ecological interactions appears to have resulted in a smaller body size. In the absence of competitors, body size tends to trend towards a size positively correlated with island area, provided that deep geological time was available to allow the dwarfing process to proceed beyond the initial phases.

Other articles related:
From giant rats to dwarf elephants, island living changes mammals

RE: The Proboscidea of the Past - brotherbear - 04-23-2016


DNA proves mammoths mated beyond species boundaries

RE: The Proboscidea of the Past - GrizzlyClaws - 04-23-2016

The interbreeding was probably occurred between the closely related Mammoth species.

RE: The Proboscidea of the Past - brotherbear - 04-23-2016

From post #7... Several species of mammoth are thought to have roamed across the North American continent. A new study in the open-access journal Frontiers in Ecology and Evolution, provides DNA evidence to show that these mammoths, which should only mate within their species boundaries, were in fact likely to be interbreeding.

A species can be defined as a group of similar animals that can successfully breed and produce fertile offspring. By using differences in the size and shape of their fossilized teeth, a number of North American mammoth species have been identified. But, some scientists are not confident this method of species categorization tells the whole story.
"Species boundaries can be very blurry. We might find differences in features of the teeth or skeleton that closely correspond to what we think are real species boundaries. But other features may not correspond to those boundaries, suggesting that what we formerly regarded as separate species are in fact not at all," explains Hendrik Poinar, a Professor at McMaster University in Canada, who co-led the new study with his former graduate student Jake Enk and collaborator Ross MacPhee, a Professor at the American Museum of Natural History.
Professor Poinar and his co-authors used cutting-edge methods to distinguish species of North American mammoths. Tiny samples of fossilized mammoth bone, teeth and faeces, were generously donated by a number of museums across America and Canada. DNA was extracted from these samples in a specialized laboratory of the Ancient DNA centre at the McMaster University, and used to create a family tree of their evolution. The results proved to be very interesting.

North American mammoths such as the Columbian and Woolly Mammoths were historically thought to originate from two separate primitive species. However, this latest DNA analysis agrees with a more recent idea that all North American mammoths originated from a single primitive species, the Steppe Mammoth.

"Individuals of the Woolly and Columbian mammoths look like they represent different species in terms of their molar teeth, but their genetics say that they were not completely separate in the evolutionary sense and could successfully interbreed," says Professor MacPhee.
Professor Poinar continues, "Mammoths were much better at adapting to new habitats than we first thought -- we suspect that subgroups of mammoths evolved to deal with local conditions, but maintained genetic continuity by encountering and potentially interbreeding with each other where their two different habitats met, such as at the edge of glaciers and ice sheets."
So, while mammoths clearly evolved differences in their physical appearance to deal with different environments, it did not prohibit them from cross-breeding and producing healthy offspring.
Despite this apparent adaptability, which should surely be a recipe for success, mammoths disappeared from the face of the Earth 10,000 years ago. "Humans are suspected to be the cause, but this is not by any means proven. Explaining the loss of mammoths and a host of other Ice Age creatures continues to be a fascinating conundrum in paleobiology," concludes Professor MacPhee. 
As well as challenging the classic method of defining a species, the authors believe the findings of this study are just the start of understanding mammoth evolutionary history. Techniques to extract and analyse ancient DNA have undergone a tremendous improvement in recent years and as these technologies continue to improve we can expect further breakthroughs.

RE: The Proboscidea of the Past - brotherbear - 04-23-2016

It appears to me to be a similar case as the grizzly and the polar bear which look very different, even down to their teeth, yet are closely enough related to successfully interbreed. 

RE: The Proboscidea of the Past - brotherbear - 05-13-2016

Another incredible discovery has been made as researchers have found a rock carving of a Mastodon at the underwater Stonehenge of Lake Michigan.
In 2007, at a depth of twelve meters, researchers found a peculiar set of aligned stones that are believed to be over 10,000 years old.
While searching for shipwrecks, archeologists from the Northwestern Michigan College came across something interesting at the bottom of Lake Michigan. They found mysteriously aligned rocks placed there by ancient man before water covered the area. Researchers couldn’t believe what they were seeing upon making the discovery. It’s America’s Stonehenge.  
*This image is copyright of its original author

RE: The Proboscidea of the Past - brotherbear - 06-28-2016

A new discovery suggests a completely different diet for Platybelodon, the strange “shovel-tusked” elephant relative.

There are only three species of elephants living today: The African Bush Elephant, the African Forest Elephant and the Asian Elephant. While being clearly different from one another, all three share the same basic characteristics: mostly hairless big bodies, thick legs, long trunks and tusks derived from the upper incisors. However, this uniformity undermines the astounding variety of extinct elephant relatives, which are collectively called Proboscideans.

There were the famous hairy mammoths and mastodons, the enormous Deinotherium with downward-pointing tusks coming out of its lower jaw, and the long-faced Gomphotherium with not only two, but four tusks coming out of its mouth. Still, one of the most bizarre extinct proboscideans was Platybelodon.

Platybelodon has puzzled scientists ever since its discovery in the early 1920s. While the overall body did resemble modern elephants, its skull indicates something very different was going on. It had a very elongated mandible from which two long flat teeth protruded, forming a distinctly shovel-shaped appendage that extended far past the upper jaw. And since we don’t have any fossilized remains of soft tissue from Platybelodon, we also don’t know for sure if it had a normal elephantine trunk, or something different like a fleshy, flat upper lip that could work alongside the strange spade-like teeth to procure food.

For many years, the consensus was that Platybelodon and similar relatives were swamp-dwellers, much like the old view of sauropod dinosaurs. They would use their shovel-mouths to scoop up soft plants from shallow waters and lead a mostly semi-aquatic lifestyle like hippos. However, recent research by paleontologist Gina Semprebon and colleagues confirmed a theory put forth in 1992 by David Lambert. The microscopic patterns of damage present on the teeth of these animals suggested that they were being used against rougher surfaces, like bark, branches and other land-based plants instead of soft aquatic vegetation, which would not cause as much tooth wear.

It now seems that the shovel-tusked Platybelodon did not use its tusks like shovels after all, but more like scythes. It had a flexible trunk to hold onto trees and branches while sawing at them with the sharp edges of its teeth to cut mouthfuls of vegetation and then bring those to its large mouth. This made them versatile terrestrial browsers much like modern elephants, while using a very different technique.

Original research published in Palaeogeography, Palaeoclimatology, Palaeoecology
Image Credit: Julio Lacerda 

*This image is copyright of its original author

RE: The Proboscidea of the Past - brotherbear - 08-29-2016

Butchered Mammoth Suggests Humans Lived in Siberia 45,000 Years Ago

By Laura Geggel, Senior Writer | January 15, 2016 03:52pm ET

RE: The Proboscidea of the Past - tigerluver - 03-03-2017

Excess of genomic defects in a woolly mammoth on Wrangel island

Woolly mammoths (Mammuthus primigenius) populated Siberia, Beringia, and North America during the Pleistocene and early Holocene. Recent breakthroughs in ancient DNA sequencing have allowed for complete genome sequencing for two specimens of woolly mammoths (Palkopoulou et al. 2015). One mammoth specimen is from a mainland population 45,000 years ago when mammoths were plentiful. The second, a 4300 yr old specimen, is derived from an isolated population on Wrangel island where mammoths subsisted with small effective population size more than 43-fold lower than previous populations. These extreme differences in effective population size offer a rare opportunity to test nearly neutral models of genome architecture evolution within a single species. Using these previously published mammoth sequences, we identify deletions, retrogenes, and non-functionalizing point mutations. In the Wrangel island mammoth, we identify a greater number of deletions, a larger proportion of deletions affecting gene sequences, a greater number of candidate retrogenes, and an increased number of premature stop codons. This accumulation of detrimental mutations is consistent with genomic meltdown in response to low effective population sizes in the dwindling mammoth population on Wrangel island. In addition, we observe high rates of loss of olfactory receptors and urinary proteins, either because these loci are non-essential or because they were favored by divergent selective pressures in island environments. Finally, at the locus of FOXQ1 we observe two independent loss-of-function mutations, which would confer a satin coat phenotype in this island woolly mammoth.