Giant Mesozoic badger turned mammalian dogma on its head

Juvenile badger with dinosaur dinner

Check your biology book. If it says anything about mammals during the age of dinosaurs, it probably depicts the mammals as small, shrew-like animals scuttering around at night, barely scratching out a living as they scurry away from the thudding feet of a Tyrannosaurus rex.

Mammals ate dinosaurs–tasted like chicken

Banish the thought and rewrite the book. Yes, many of the mammals that lived in the Mesozoic—from about 248 to 65 million years ago—were shrew- or rat-like critters that probably stayed out of the way of most dinosaurs. But recent fossil finds demonstrate that some of the mammals in the age of the dinosaur not only got in the path of dinosaurs, they ate them.

In China, there is a famous fossil bed best known for the fossils of feathered dinosaurs it has yielded. But paleontologists have also turned up some other intriguing remnants, among them the mineralized bones of species from the Repenomamus genus. These animals were long, squat-bodied creatures with strong jaws and very sharp, pointy teeth. Researchers at the site had already reported finding R. robustus, a carnivorous mammal weighing in at about 15 pounds.

Giganticus, indeed

But two other finds reported in Nature flip common Mesozoic mammal dogma upside down. The first discovery was that of a fossil species now dubbed Repenomamus giganticus, a cousin of R. robustus, but with some distinctive features: this specimen probably weighed about 30 pounds and grew to be up to a meter long. Think about a mid-sized dog, say a large basset hound, with a badger-like face and rodent-like sharp teeth, and you’ve got your R. giganticus. Not something you’d want to go hand-to-tooth with when it’s in a bad mood.

Died with dinner inside (& more dog breed comparisons)

That, at least, is what researchers concluded after their second find: a fossil of R. robustus, the smaller species, with a juvenile dinosaur skeleton where the R. robustus stomach would have been. Not only did these hardy Repenomamus species look scary, for juvenile, leaf-eating dinosaurs, they were deadly. Experts estimate, based on mammalian habits of today, that mammals can kill and consume prey that is up to half of their body weight. If R. robustus could snack on a 5-inch dinosaur baby, then presumably R. giganticus could have put back a dinosaur the size of a dachshund.

The scientists who identified and named R. giganticus had a couple of hurdles to overcome. First, they had to determine that this was a genuine average version of R. giganticus, not simply R. robustus with a pituitary problem. The error that would result would be akin to finding the skeleton of the world’s tallest man and assuming that it represented our entire species.

Badger or human, your teeth show your age

But they looked at the teeth that accompanied the skull and jaw fossils, and the molars held the clues to the animal’s age at death. The last molar of the lower jaw appeared to have just erupted when the animal died, and it had little wear. Based on this clue, the researchers concluded that fossilized remains were from a juvenile representative of the new R. giganticus species.

Making the case that a Mesozoic mammal had actually consumed a dinosaur also required some consideration and discarding of various possibilities. The little dinosaur skeleton, from a Psittacosaurus, was a small patch of bones within the ribcage of some R. robustus fossil remains. The bones were located right where the stomach is on today’s mammals, and appeared to have been broken, torn apart, and displaced from one another. The fossil bones of the accompanying R. robustus skeleton were not in this condition. The Psittacosaurus specimen also had teeth, most of which were worn, implying that this animal was not scavenged from an egg as an embryo. Based on these clues, the researchers concluded that this R. robustus had caught and eaten the hapless Psittacosaurus—dismembering it and swallowing it in chunks—shortly before meeting its own death.

Chinese winemaking aged 9000 years

Tracking ancient alcohol production is tough

The fermented grain has been the centerpiece of much of the development of human civilization. According to archaeologists, wines and beers contributed to the formation of religious practices, commerce, social interactions, and community structure. So it’s only natural that we would want to find out how and when we began purposely making such beverages to imbibe.

But alcohol evaporates easily, and being a liquid, isn’t usually preserved for archaeologists to discover thousands of years after the fact. Yet scientists have managed to get lucky and to apply a little smarts to figuring out the mysteries of ancient alcohols, and some of the best information on such beverages is now coming out of China.

The dawn of “real” human civilization?

In China, there is a famed Neolithic archaeological site where some of the oldest musical instruments and Chinese pictographs have been found. The Neolithic age, or New Stone Age, dates back to about 8000 or 9000 years, and this particular site in northern China has yielded abundant resources for investigations into the period, often viewed as the dawn of real human civilization.

Among these resources are pieces of pottery from vessels used to hold liquids. Researchers determined that these pots probably held fermented beverages because they were so similar to vessels from later periods that were known to have stored wines. To investigate their ideas, they collected pieces from the bottoms of 16 different vessels from the northern China site. The bottoms of the pots, they reasoned, would have absorbed more of the liquid and precipitates than the sides, and would thus yield more information.

Archaeo-chemists identify fine old vintage

Using various methods to identify the chemical makeup of the residues on the pots, the archaeo-chemists, as they are called, determined that the vessels once held wines made of rice or millet and flavored with tree resins, honey, and flowers. The methods they used, which included gas and liquid chromatography and mass spectrometry, pinpointed the flower residues as hawthorn or wild grape. One key component they identified was tartaric acid, which is the primary organic acid in grape wine.

At the same time they were performing these analyses on pot fragments from a 9000-year-old village, the scientists were also investigating the evidence from another lucky find. They had discovered some vessels that were part of a burial site for elite individuals living during Shang and Western Zhou dynasties, from about 1250 to 1000 B.C. These vessels had become tightly sealed as their lids had corroded and formed a barrier around the top. Perfectly preserved inside were the liquids they held, probably intended as accompaniments for the dead on their way to the next world, or possibly used in burial or visitation rituals.

Truly ancient Chinese recipes

The archaeo-chemists analyzed the contents, which looked and smelled very like the rice and millet wines that are still made today in China. They found that the vessels contained wines made of the very same components as those identified in the 9000-year-old pot fragments from the Neolithic village. The recipes appear to have been used for millennia.

The finds also indicate that the people who made the wines had a sophisticated understanding of the fermentation process. They used cakes made of various molds to break down the carbohydrates in rice or millet into simple, fermented sugars. They appear to have known that substances like wormwood—which was found in the Shan/Western Zhou analysis—would enhance the fermenting activity of the yeast considerably.

A Chinese record–for now

China now holds the record for the world’s oldest known human-directed fermentation. Iran held the previous record, based on wines found in two jars at a Neolithic site dating to 5400 B.C. The oldest known reference to a fermented beverage recipe comes from Iraq, where a clay tablet mentions how to brew beer as part of a hymn to the goddess of brewing.

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