Lucy’s Monstrous Misfits II: Upside-Down Mastodon

Dr. Bakker’s series on Lucy continues below. Check out  Part 1: Lucy – Out of Africa. Not! and Part 2: Lucy’s Monstrous Misfits: The Moose-Giraffe.

Why did some of Lucy’s neighbors score big bio-geographical successes, spreading over many continents?

Three More Cases: Hairy Monsters With Tusks & Trunks

Elephant bull 2
Creative Commons License photo credit:
Tambako the Jaguar (on the sea)

The Order Proboscidea includes all elephant and elephant kin – large to giant to super-giant herbivores with long upper lips transformed into trunks, plus long tusks. Tusks can sprout from the upper jaw or the lower jaw or both jaws.

Regular Short-Tusked Mastodons – “The Ohio Incognitum”

Regular Mastodons were the first fossil Proboscidea to be discovered – way back in the early 1700’s.  The legs looked like elephants’. The teeth looked like giant pig teeth.  Explorers in the Ohio Valley called the monster the “Unknown  Creature (Incognitum) from Ohio.” Formal name: Mammut.

By the late 1700’s full skeletons showed the whole beast – it was very like an elephant but shorter with a low forehead and short, stout upper tusks.  Lucy lived with Regular Mastodons who were very close to the Ohio Beast.

Regular Mastodons – The Long-Tuskers (Anancines)

DeinoAnancine copyLiving side by side with the Ohio Regulars in Lucy’s Africa was a close relative: The Long-Tusked Regulars. Technical name: the Anancine mastodons. In the Anancines, the super-long tusks stuck out so far we’d expect the beast to trip itself if it ran fast.

Upside Down Mastodon.

Now for the maximum weirdness among proboscideans: the Deinotheres.  Large to super large, Deinotheres had a long, long history in Africa, beginning way before Lucy or any other australopithecine. Body was elephantine – but the feet were small, with tiny side toes and three big ones in the middle.

The astonishing feature was the curved tusks. They were upside down. Instead of being in the upper jaw and curving up, the way they did in all normal mastodons, Deinothere tusks curved down and were in the lower jaw.

What good were upside-down tusks?

Old-timer scientists speculated:

“Maybe they hauled themselves out onto ice flows, like walruses do.”

Wrong. Deinotheres never lived in cold regions.

“Maybe they killed their prey with a downward jab.”

Wrong.  Deinothere molars were vegetable choppers, designed to munch big leaves and branches. All deinotheres were vegetarian.

“Maybe they used the tusks to cash down onto branches to break them off.”  “Maybe they fought each other in the mating season.”

Maybe.

World MapDeino

As global travelers, Deinotheres are intriguing. They were like hippos. Deinotheres spread over Europe and India and China. But they never conquered Siberia and never entered the New World, via the Bering Land Bridge.

Makes you think……

Why?

Lucy’s Monstrous Misfits: The Moose-Giraffe

Dr. Bakker’s series on Lucy continues below. Check out Part 1: Lucy – Out of Africa. Not!

Our Lucy and her kin were surrounded by hairy monsters – there were more kinds of multi-ton mammals than at any other time in Darwinian history.

Lots looked “normal.” There were a half-dozen species that were elephant-shaped, more or less. And there were rhinos, both black and white, who would look perfectly acceptable today in the Bronx Zoo.

Then there were the Evolutionary Misfits.  These fellows seemed put together from the front half of one species and the rear from another – with odd legs and horns thrown in.

Perfect Misfit Example – The Moose Giraffe

Sivathere copyThis beast was first discovered in Pakistan and northern India where it was christened “Sivatherium” – for the Hindu God Shiva.  The Moose-Giraffe did look like something out of a mythological-theological  fantasy. Sivatheres were the tallest and fastest of the maxi-monsters, up to fifteen feet or more, hoof to eyeballs. Their body was bulky, in the elephant size-range.  Sivatheres were faster than elephants – they had long, strong legs that combined features of Cape Buffalo and a giant moose. If Lucy ever saw a bull sivathere charging downhill in a hurry, she’d have to get out of the way, fast.

Sivatheres had moose-muzzles. The upper lip and nostrils were carried in a bulbous, muscular schnoz that could grab branches or lift out water plants from ponds.

When Antlers are Not Antlers

At a distance, you’d think sivatheres carried moose-antlers, heavy bone growths that branched and re-branched.  One difference: both male and female sivatheres had them (only male moose today are antlered.) And…if you got close, you’d see something else that was un-moose-like. There was no drop-spot. Moose are deer, and all deer shed their antlers after the breeding season. The main antler falls off, leaving a stub attached to the skull. There’s a rough zone on the top of the stub where the main antler is shed and a new one will grow up next year.

Sivatheres had no drop-zone. Their “antlers” kept growing and growing, all through life.

Therefore – we can’t call the sivathere horny growths “antlers.” We have to call them “horns.”

Plus – Moose Giraffes have too many horns. There are the big, tall, branched things in the rear. And then smaller, sharper, pointier horns in front. Those front horns look like……giraffe horns.

Horns – Hard on the Inside, Soft on the Outside

Beautiful Giraffe
Creative Commons License photo credit: Rennett Stowe

That was the tell-tale clue. Details of teeth told the same story. Sivatheres were part of the giraffe family and NOT moose relatives. Giraffes today grow horns like a sivathere’s but smaller and less complicated. The giraffe family builds their horns in a unique way. Most horned beasts today – antelope, cows and buffalo – have an inner horn made out of bone and an outer horn made out of very hard, tough, dead skin. Giraffe horns are built differently: there’s an inner bone horn but on the outside is a layer of soft skin.

What kind of outer horn did sivatheres have? Skin rots before fossilization. Still, we can tell what kind of covering sivathere bone horns had. Sivathere fossil horns have the same texture on the outside that giraffe horns do – a pattern of small pits, for blood vessels. This texture proves that sivathere horns had soft-skin on the outside.

World MapColSiva copyNo Entry Into the New World

Sivatheres are a geographic puzzle. They spread all over India and Pakistan and Central Europe, then down through Africa. But they avoided northern Asia and Europe. And Moose-Giraffes were shut out of North America.

Why?

If we can figure out what stopped sivatheres, we’d have help figuring out Lucy’s travels.