The skulls of four hundred wolves are suspended before me. An orange backlight reveals their silhouettes aligned in perfect rows, and for a moment, I think of an army of ghosts. I look at them one by

one,empty but orbits. they After don’t a while,stare back the dead from wolves their disclose some long-gone stories: a broken tooth, a deep scar on the bone, the delicate features of a young one who never became an adult.

I am not describing a bad dream. several thousand years old. historic ecosystems and the animals This actually happened during The ancient pools of natural asphalt that once populated them. my last visit to La Brea Tar Pits in pouring out of the ground at La Brea When I was a kid, paleontology Los Angeles. In one of the sections were often concealed by a layer of seemed pretty straightforward: I of the La Brea museum, there is leaves and debris that turned them deduced that in time, dire wolves a dramatic wall displaying the into a deadly trap. Animals who unin- became our wolves of today in the skulls of 404 individuals of an tentionally walked on these pits found same fashion saber-toothed cats extinct species known as the dire themselves permanently glued to a became our tigers, right? Wrong. I was wolf (Canis dirus). These wolves melting landscape and their remains in for a shocker when later I learned were not the victims of a tragic attracted carnivores and scavengers that dire wolves actually shared the single incident: they died over a who also got trapped. The carcasses landscape with our modern gray span of many thousands of years. of these animals eventually sank and wolves (Canis lupus). Evolution is not Some of these skulls look like they the tar preserved their bones in excel- as simple as that ten-year old thought! lent conditions. Millions of bones have The ancestry of wolves is a puzzling - been recovered at La Brea, allowing tale and the blanks on the map have sionwere – onthe themost forest recent floor of them only are a researchers to learn more about pre- few years ago, but that’s an illu fueled scientific debate for many 12 wolf tracks | WINTER 2016/2017 - and its story can be traced up to ing story. survival and the dire wolves became 40 million years ago, to a geologic years.The That’s dire wolfwhy it’swas such formidable, a fascinat extinctand stronger about don’t10,000 necessarily years ago. meanThey epoch known as the Eocene. similar to our gray wolf but much were not alone; dozens of species In that era, the polar ice caps more robust, with larger teeth, a of big-bodied animals known as the were absent and the world was stronger bite force and proportion- prehistoric megafauna disappeared much warmer and humid than ally shorter legs – a wolf on steroids! in a planetary event known as the today, favoring luxuriant tropi- It was a success in its time, to the Quaternary Extinction. This collective cal forests in unlikely places like point of being hailed by researchers vanishing act has been explained by a Wyoming and Germany. This is as “the most common fossil canid in combination of two scenarios: extreme when the family of wolves had a North America.” Studies of inorganic climate changes and excessive hunting humble start in the form of small by modern humans. creatures no larger than a corgi; show they fed on animals like horses, Dire wolves, however, were a rather since then, the fossil record has mastodons,compounds camelson dire andwolves’ terrestrial bones modern twig in the wolf family tree. yielded more than 200 species sloths the size of bison. Contrary to The family known as Canidae or of canids, most of them becom- some popular misconceptions, bigger canids, originated in North America ing extinct through time, leaving

WINTER 2016/2017 | wolf tracks 13 us with the 37 or so species existing America. The old dogs were about to caribou and other megafauna associ- today. There have been wild dogs of learn new tricks by traveling. ated with the Arctic regions. Then the all sizes and shapes. A species of the As canids radiated through Eurasia, gray wolves dispersed through the Old genus Epicyon (from the Greek “before they adapted to new habitats, forming World, reaching the coasts of Northern dog”) that originated about 12 million a vast arrange of novel species. About Africa. Eventually they also crossed years ago, was the largest canid we 1.8 million years ago, at the beginning know of and it stood as tall as a small of the Pleistocene (aka Ice Age), there North America, the original cradle of lion; this ferocious looking animal had was such a melting pot of canids that theirBeringia, dynasty. finding their way towards a strange short-face as an adaptation some refer to this time as the “Wolf So the old dire wolf perished. It is to increase bite power, allowing it to Event.” Some forms of these ancestral believed that its demise was related to crack bones and extract the nutritive wolves were so similar to each other, what once allowed it to thrive – spe- marrow. There were also less dramatic cialization. It was too well-adapted to dogs, like a delicate foxlike species of lineage gave origin to whom. the genus Otarocyon (“large-eared thatThe often lower it’s hardtemperatures to establish during which adapt fast enough to changes, the dire dog”), who might have looked pretty the Ice Age also generated drier and wolfhunt followedgiants and them when to itsthe prey end ofdidn’t the much like our modern fennec foxes of more seasonal conditions and the line. The gray wolf prevailed instead, the Saharan desert. landscape in higher latitudes went and became the most widely distrib-

Most of the evolutionary history of from dense forests to vast grasslands. uted species of terrestrial carnivore. canids happened in North America in Herbivores had to adapt by increasing relative isolation from the rest of the resiliency and legendary capacity to world. But this changed about 7 or 8 and since living in open country travel,The gray’s but its success longest has journey to do has with been its million years ago when the cooling of exposedtheir efficiency them inmore consuming to predators, grasses through time, witnessing the end of our world led to the formation of the they also had to become faster. Canids mammoths and the rise of human cit- polar ice caps, while massive glaciers literally had to keep up, so long legs, ies. The elk, the caribou, the conifer trapped so much water that sea levels large bodies, stamina and coordinated dropped hundreds of feet in some group hunting were adaptations that be what they are without the presence shores. This caused the emergence of a allowed them tackle fast prey in mov- offorests the wolf. and Theythe Great all shape Plains each wouldn’t other. massive land bridge in a region known ing in herds. Put all these ingredients This evolutionary tale is not meant to as Beringia (the modern Bering Strait), together and you have discovered the end in a museum, because it is far from allowing an intercontinental migration universal recipe for wolves. ending: the story of the wolf is still of species and the exploration of new It is believed that our modern gray happening out there, in the living environments. Three million years wolf (Canis lupus) originated some- wilderness around us. later the Panama isthmus emerged too, where in Eurasia about 800,000 years opening the faunal trade with South ago, coexisting with mastodons, bison, – Chris Montero, Outreach Coordinator 14 wolf tracks | WINTER 2016/2017