Posts Tagged ‘Panthera spelaea’

2 New Studies of Pleistocene Lions

January 6, 2019

There were 3 species of lions living on earth during the late Pleistocene.  The African lion (Panthera leo) is the only species still extant.  The cave lion (P. spelaea) ranged across Eurasia from Britain to Beringia which included Alaska and Yukon above the Canadian Ice Sheet.  The giant American lion (P. atrox) lived in North America south of the Ice Sheet from California to Florida.  Some taxonomists formerly thought the 3 lions were the same species, but recent analysis of anatomy and genetics determined they were 3 distinct species.

2 new studies of Pleistocene lions were published last year.  The first study described an unusually large lion skull found in Natodermi, Kenya.  This specimen is estimated to be 196,000 years old. On average cave lions and giant American lions were larger than African lions.  P. atrox was the largest species of lion, averaging 25% larger than African lions, and 1 specimen is estimated to have weighed over 1000 pounds.  (See https://markgelbart.wordpress.com/2017/01/31/panthera-atrox-the-1007-pound-giant-lion/ )   However, the specimen described in this new paper (catalogued as #KNM-ND59673) belonged to an individual that may have been larger than any cave lion specimen ever described and even larger than all but 2 known American lion specimens.  The size comparison estimates in this paper were based on dental dimensions.  The authors of this paper believe this individual was part of an extinct population that grew to a larger size because they hunted an extinct species of large buffalo (Syncerus antiquus).  They think it was a subspecies of African lion related to the ancestors of the 2 regional haplotypes of lion that still occur today.  Genetic evidence suggests northern lions diverged from an ancestral population of lions 147,000 years ago, while southern lions diverged 189,000 years ago.  This specimen was found on the border between the 2 modern haplotypes.  Although they don’t think it was a distinct species, they can’t completely rule it out–there just isn’t enough evidence.  It seems likely some Pleistocene African lions were just as large as the other 2 species.  Lions originally evolved in Africa but fossil evidence from that continent is more rare than in Eurasia and North America.

 

196,000 year old African lion skull.

Image result for syncerus antiquus

Pleistocene lions may have grown larger in Africa to help them bring down this large extinct species of buffalo.

The 2nd study described 4 specimens of cave lion found in Medvedia Cave located in the Zapadne Tatry Mountains.  These mountains border northern Slovakia and southern Poland. Referring to this species as the “cave” lion is misleading.  Most individuals never went inside a cave during their entire life.  A cave environment is just 1 of the rare places where their remains could be preserved.  Medvedia Cave is the highest altitude that a lion fossil has ever been found.  The authors of this paper think lions searched through caves for hibernating bears, and groggy bears may have been an important part of high altitude lions’ diets because other substantial prey was scarce here.  Some scientists think cave lions were solitary hunters or perhaps hunted in pairs, unlike social African lions that live in large prides.  I disagree with this notion.  Adult male lions grow too large and bulky to hunt prey effectively, and they depend upon females to bring them food.

Lions were more widespread during the Pleistocene because human populations were sparse.  Humans have outcompeted lions since then.  If not for the rise of humans, lions would still be just as widespread as they used to be.

Reference:

Manth, F. ; et. al.

“Gigantic Lion, Panthera leo, from the Pleistocene of Natodermi, eastern Africa”

Journal of Paleontology 92 (2) Novemeber 2018

Sabol, Martin; Juraj Gullar and Jan Harrat

“Montane Record of the Late Pleistocene Panthera spelaea (Goldfuss 1810) from Zapadne Tatry Mountains (northern Slovakia)”

Journal of Vertebrate Paleontology  38 (3) 2018

See also: https://markgelbart.wordpress.com/2016/01/07/uf9076-a-complete-skull-and-jaws-of-a-giant-lion-panthera-atrox-found-in-the-ichetucknee-river-florida/

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A New Study of Pleistocene Lion (Panthera spelaea) Genetics Confirms it was a Distinct Species

August 29, 2016

A couple of my readers brought 2 new studies of lion genetics to my attention.  One of the studies confirms the notion that the extinct Eurasian lion (Panthera spelaea) was a distinct species from the present day African lion (Panthera leo).  (See: https://markgelbart.wordpress.com/2012/05/02/three-pleistocene-lions-were-they-distinct-species-or-the-same-animal/ ) The scientists who co-authored this study analyzed the DNA from 2 ~30,000 year old specimens of “cave” lions and used it to compare with the DNA of other felid species.  They extracted the DNA from a lion arm bone found in Yukon, Canada and some lion hair preserved in Siberian permafrost.  The study suggests Panthera spelaea and P. leo were sister species that diverged ~1.89 million years ago.  This divergence precedes the oldest known lion fossil by over 1 million years.  Panthera fossilis, an extinct archaic species of lion, was thought to be ancestral to both P. spelaea and P. leo.  However, this species lived 700,000 years ago, and the divergence likely occurred before P. fossilis evolved.  Fossils of a cat in the panthera genus that date to 3.5 million years ago have been found in Africa, but not enough skeletal evidence exists to narrow it down to species level.  P. spelaea certainly evolved a greater physiological adaptation to colder climates at the beginning of the Pleistocene as periodic Ice Ages became more severe in Eurasia.  This physiological difference may explain the speciation event that separated P. spelaea from P. leo.

Although this study didn’t examine Panthera atrox, the species of lion that occurred across North America south of the Cordilleran Glacier, the results do make it seem more likely that it too was a different species.

Specimens used in the below referenced study–a lion arm bone found in the Yukon and a hair sample found in Siberian permafrost.

The other study looked at the genetics of present day lions living in Africa and India.  This study determined there are 6 distinct regional breeding populations of lions–the west, central, northwest, northeast and south Asian, east/southern, and southwest.  These breeding populations have been repeatedly isolated from each other because of altered landscapes influenced by cyclical Pleistocene climate changes.  Lions prefer open savannah habitats but avoid thick tropical jungles and large deserts.  A belt of monsoons currently brings heavy rain to west central Africa, but this monsoon belt shifts every ~21,000 years, changing the zones of tropical forests and deserts.  Populations of lions become isolated from each other when their favored savannah habitat fragments and is separated by forest and desert.  Other species of savannah habitat show similar intraspecific genetic isolation including giraffe, water buffalo, bushbuck, waterbuck, hartebeest, warthog, cheetah, and spotted hyena.

The common ancestor of all present day clades of African lion diverged ~245,000 years ago.  The genetic evidence suggests all clades of lions were relegated to small refugia during the Last Glacial Maximum when much of Africa hosted landscapes unsuitable for the big cats.  Humans have recently translocated lions from different regions into other regions in an attempt to rebuild populations.  This interference results in the crossbreeding of different clades with each other.  Zoo lions are also crossbred clades for the most part.

References:

Barnett, Ross; et. al.

“Mitogenetics of the Extinct Cave Lion, Panthera spelaea, Resolve its Position Within the Panthera Cats”

Open Quaternary June 2016

Bertoli, L.S.; et. al.

“Philogeographic Pattern in Africa and High Resolution Delineation of Genetic Codes in the Lion (Panthera leo)

Scientific Reports May 2015

 

Surprising Discoveries of Large Carnivore Dietary Preferences on the Pleistocene Mammoth Steppe

May 2, 2015

The mammoth steppe was a vast continuous environment that stretched from western Europe to Alaska during the coldest phase of the most recent Ice Age.  Glacial ice locked up so much of earth’s atmospheric moisture that sea level fell, creating land bridges connecting the British Isles and Alaska with Eurasia.  The mammoth steppe consisted of desert grassland, cold and windy but without much snow cover.  This environment supported a wealth of megaherbivores including woolly mammoth, bison, yak, musk-ox, woolly rhino, horse, megaloceros (a giant deer), caribou, camel, and saiga antelope.  Such a wide prey selection attracted several species of large predators.  Scientists long speculated about the relationships between predator and prey on the mammoth steppe, but now it’s possible to determine which prey species each individual species of predator favored.   In an ingenious study, Herve Bocheren, a German professor, used stable isotope tracking in combination with mathematical models to learn about the diet of late Pleistocene carnivores on the mammoth steppe.  Some of his findings are quite surprising.

fig 2

Map of the vast mammoth steppe ecosystem that existed between ~28,000 BP-~15,000 BP.

Various species of plants have distinct ratios of carbon and nitrogen isotopes, and therefore herbivores that eat these plants have similar ratios in their bone chemistry.  Carnivores that then eat these herbivores also attain these distinct ratios of carbon and nitrogen isotopes.  By analyzing the chemistry of ancient bones found in caves, the diets of these animals can be pieced together.

Stable isotope tracking suggests the spotted hyena (Crocuta crocuta) was the dominant predator in Europe until about 25,000 BP–before climatic conditions caused the expansion of the mammoth steppe grassland.  Between 60,000 BP-28,000 BP forests and open woodlands still grew amidst the grasslands, and climate remained temperate though there were rapid fluctuations.  The spotted hyena, the same species found in Africa today, thrived in temperate climates, and they outcompeted wolves, lions, and even Neanderthals here during this time period.  Isotopic evidence shows hyenas ate a wide range of prey including mammoth, horse, and rhino; relegating wolves to prey such as elk, giant deer, and chamois.  But hyenas were unable to survive in Eurasia during the following colder climate phase, and they became extirpated from the mammoth steppe.  Hyenas must have a limiting minimum temperature limit that they can endure.

The  most surprising result of Dr. Bocheren’s study was the discovery that cave lions (Panthera spelaea) relied on caribou for at least 25% of their diet.  The lion of the mammoth steppe was not the same species as the African lion (Panthera leo).  It was 10% larger but males had smaller manes.  The evidence from this study supports conjecture that it was a solitary predator, unlike its extant cousin.  Packs of hyenas and wolves were able to restrict access of this solitary predator from more desirable prey such as bison and horse, forcing cave lions to rely more on caribou.  There is also a great variation in each individual lion’s choice of prey.  One individual favored caribou and deer.  Another specialized in cave bear but also took mammoth, deer, and rhino.  A 3rd individual fed upon cave bear and deer.  And a 4th ate the same mix of desirable prey that hyenas ate.  Each individual learned to hunt certain prey animals, whereas a social predator would’ve likely taken a wider mix of prey.  An individual lion killing an huge cave bear must have been an impressive sight.  There is also fossil evidence of lion bite marks on bear bones.  Today, certain Siberian tigers are known to specialize in hunting brown bears (Ursus arctos).

Dr. Bocheren studied the bone chemistry of scimitar-toothed cats (Dinobastis serum or Homotherium serum depending on whose nomenclature one chooses) as well.  Unlike saber-tooths (Smilodon fatalis) this fanged cat was not an ambush predator but chased down its prey instead.  Complete skeletons of scimitar-toothed cats have been found in Friesenhan Cave, Texas associated with many bones of juvenile mammoths.  Because of this single site, scimitar-toothed cats were thought to be specialists in hunting juvenile mammoths.  This study casts doubt on that assumption.  Instead, the favorite prey of scimitar-toothed cats in Eurasia was the yak (Bos grunniens), along with bison and caribou.  Less commonly, they did eat musk-ox, mammoth, and horse.  They were a generalized predator, not a specialist.  Scimitar-toothed cats are rare in the fossil record compared to other large carnivores and probably were extirpated from the mammoth steppe along with hyenas and leopards when the climate deteriorated about 25,000 BP.

Painting of lions on a wall in Chauvet Cave, France.  Looks like the representation of a pride of lions.  I’m not convinced the extinct European cave lion was a solitary animal as suggested by this study.

The yak (Bos grunniens).  Isotopic tracking studies suggest this was the favored prey of the extinct scimitar-toothed cat.

Wolves (Canis lupus) replaced hyenas as the dominant predator in Eurasia after 25,000 BP.  There was a wide genetic and morphological diversity among Pleistocene wolves on the mammoth steppe.  The large extinct Pleistocene wolf ecomorph that lived in Alaska ate mostly horse, bison, and caribou but not mammoth.  This line of wolves became extinct.

Isotopic evidence shows Paleolithic humans living about 28,000 years ago ate mammoth but did not allow their primitive dogs to consume the mammoth meat.  Instead, humans fed their dogs caribou and musk-ox.  However scavenging predators such as wolf, brown bear, wolverine, and fox did take advantage of anthropogenic mammoth hunting.

Dr. Bocheren’s isotopic study confirms the cave bear (Ursus speleus) was almost entirely herbivorous.  Brown bear diet varied.  Brown bears were more carnivorous in regions where they overlapped with cave bears but were more herbivorous in regions where they overlapped with highly carnivorous giant short-faced bears (Arctodus simus).  Brown bears apparently avoided completion with larger bear species.  In Alaska giant short-faced bears ate caribou, musk-ox, and other predators but plant foods may have made up to 50% of their diet.  Surprisingly, they didn’t eat much horse or mammoth–2 common prey species here.  The diet of this North American species south of the ice sheet has not yet been studied.

Note 1: I think the common names of cave lion, cave bear, and cave hyena are misnomers.  99.9% of the individuals of these species that ever lived never stepped inside a cave.  There bones were more likely to be preserved in caves, hence the cave appellation.  Nevertheless, it’s misleading to think of them as cave dwellers.  This is just a pet peeve of mine, but I wish they would be given different common names.

Note 2: I’m not entirely convinced that Panthera spelaea was a solitary species, nor am I convinced this species played second fiddle to wolves and hyenas.  I’ll think more on this and perhaps comment at a later date.

Reference:

Bocheren, Herve

“Isotopic Tracking of Large Carnivore Paleoecology in the Mammoth Steppe”

Quaternary Science Reviews March 2015