Welcome back to the Abstract!
This week, let’s get our hands dirty by digging deep into a bunch of dinosaur poop, puke, and guts that dates back about 200 million years to the Triassic-Jurassic transition. An amazing story, written in filthy fossilized ink, reveals how dinosaurs ate, crapped, and barfed their way to world domination.
Then, ancient needles at a camp in Wyoming hold clues about the tailored garments that prehistoric peoples depended on for comfort and survival. Next, a squirting cucumber goes ballistic—literally. And if you’ve ever felt stressed out about your social standing, there are fish who understand. I hope it was a happy Thanksgiving to all who celebrate, and a restful end of November to everyone else.
The Rise of the Dinosaurs, According to Poop, Puke, and Guts
The fossil record preserves the bones and tracks of extinct creatures, but it is also packed with heaps of poo, puke, and other delightfully yucky stuff from digestion systems of the deep past. These trace fossils are collectively known as bromalites, a category that includes coprolites (fossilized poop), regurgitalites (fossilized upchuck), and cololites (fossilized guts).
Bromalites are incredibly useful datapoints because they expose the contents of bygone stomachs, allowing researchers to reconstruct diets and food webs with direct evidence that is absent from other parts of the fossil record.
Scientists have now dropped a bomb of a bromalite study that analyzes a whopping 500 poopy, barfy specimens that span the transition from the late Triassic to the early Jurassic periods, which played out from about 210 to 180 million years ago. This was the era when dinosaurs first took over Earth, displacing other animals in similar niches to become the most dominant group for the next 170 million years.
“Here we analyse the rise and early evolutionary radiation of dinosaurs using a completely new approach,” said researchers led by Martin Qvarnström of Uppsala University. “We used an array of methods, including synchrotron microtomography, to perform analyses of more than 500 bromalites (coprolites, cololites and regurgitalites) and other fossils with direct evidence of feeding (for example, bones with signs of predation/scavenging).”
Bromalites “increase in size and diversity across the interval, indicating the emergence of larger dinosaur faunas with new feeding patterns,” the team added. “Our results support the idea that stochastic processes coupled with a competitive advantage paved the way for the enormous evolutionary success of dinosaurs.”
The story unveiled through this lens unfolds in five parts. It begins with early dinosaur ancestors who leaned into omnivory, enabling them to edge out non-dinosaur animals that had more specialized diets. That was followed by the emergence of small theropods—the clade that eventually produced raptors, tyrannosaurus, and birds—which were the first carnivorous dinosaurs. In part three, dinosaurs caught a lucky break from a major bout of climate change that created landscapes with more diverse plant life, a diet favored by herbivorous dinosaurs, including the ornithischian precursors of Triceratops. The dinosaurs get bigger and more diverse in part four, a shift marked by the entrance of sauropods, the long-necked herbivores that ultimately became the largest animals ever known to walk on land. Part five: World domination.
It’s an amazing tapestry to weave together with scatalogical threads, but the best part of the study might be all the finer details about the specimens. Bromalites from Lisowicia, a wild-looking competitor to early dinosaurs, showed it ate almost exclusively conifers, foreshadowing the disadvantage these specialized eaters would later confront in environments with more diverse flora. Bromalites from herbivorous dinosaurs in the early Jurassic contain charcoal, revealing that these animals were eating wood that was burned and charred from widespread wildfires at the time. But perhaps the gnarliest bromalites come from carnivorous dinosaurs, which would regularly poop out bones and skulls.
“Theropods, known from up to 55-cm-long tracks, probably produced the large bone-bearing bromalites” including one containing the “skull and limb elements of an early crocodylomorph,” the team said. “However, the menu of these large theropods probably extended far beyond crocodilians, as evidenced by the presence of fish scales and bone fragments of much larger prey items, which probably represent large sauropodomorph rib or limb fragments.”
First of all, I’m always a fan of using the word “menu” in this context, because it makes me imagine a theropod at a fancy dinner table ordering a crocodilian a la carte. But more importantly, these bromalites open a window into the bellies of these beasts, yielding insights into how dinosaurs ascended to a reign so awesome that an extraterrestrial deathbringer was ultimately required to end it. We can glimpse everything from scorched landscapes to grand migrations through these digestive remains.
The study is also a wonderful reminder that bodies have been dumping goopy waste out of one end or the other for time immemorial on this planet. May this add some purpose and grandeur to your next visit to the restroom.
Stitching Together the Story of Prehistoric Garments
The phrase “clothes make the man” hints at the social judgment that we all receive for our sartorial choices, but there is also an unintended and literal side to this aphorism—the evolution of humanity has been profoundly shaped by tailored garments. Needles made of bones have provided indirect evidence of these garments at archaeological sites dating back as far as 40,000 years. Now, archaeologists working at the LaPrele Mammoth site in Wyoming have identified some of the animals used to make these tools for the first time.
“Of the various technologies and behaviors enacted to cope with cold temperatures, complex, tailored garments are among the most important,” said researchers led by Spencer Pelton of the University of Wyoming. “Despite the importance of bone needles to explaining global modern human dispersal, archaeologists have never identified the materials used to produce them, thus limiting understanding of this important cultural innovation.”
Pelton and his colleagues analyzed dozens of needles from this ancient hunting camp where Paleoindians once butchered a mammoth. They discovered that needles were commonly crafted from fur-bearing animals like foxes, hares, rabbits, bobcats, lynx and possibly the American cheetah, which has since gone extinct.
“Our results are strong evidence for tailored garment production using bone needles and fur-bearing animal pelts,” the team concluded. “Such garments might have looked comparable to those of the Inuit, who sewed fur-bearer pelts into the fringes of parkas whose base material was typically comprised of ungulate hide and used them for hats and mittens.”
Damn, that sounds cozy. As temperatures plunge across the Northern Hemisphere, remember that your warm winter-wear was pioneered by people who had to stitch to survive.
The Stressful Lives of Subordinate Cichlid Fish
Animals that live in hierarchical social structures receive all kinds of positive and negative information about their status, access to resources, and reproductive prospects. Now, scientists have zoomed in on how all these pressures affect the brains of the highly social cichlid fish Astatotilapia burtoni.
Dominant males of this species are more brightly colored, territorial, and reproductively successful than subordinate males—though interestingly, subordinates can become dominant, and vice versa, depending on their environment. Scientists studied the dissected brains of fish from both male phenotypes, and discovered that subordinates were generally more stressed, though dominant fish also experienced some stress in different parts of the brain.
“Social stress can increase reactive oxygen species and derail antioxidant function in the brain, which may contribute to the onset and progression of mental health disorders,” said researchers led by Peter Dijkstra of Central Michigan University. “In hierarchical species, repeated social defeat can raise oxidative stress in the brain.”
“Our findings show that both antioxidant capacity and oxidative DNA damage are impacted by social status but these effects varied by brain division and were marker specific,” the team said. “These general findings are consistent with the idea that distinct social challenges experienced by dominant and subordinate males could impact patterns of oxidative balance in the brain.”
There’s something so perfectly devastating about the phrase “repeated social defeat.” If you've ever been stressed about your social life, these fish are a remdiner to cut yourself some slack for the sake of your brain.
The Secrets of a Ballistic Squirter
Nature is filled with innovative means of dispersing seeds, but the squirting cucumber is one of the only species that decided to go ballistic with it. This flowering plant, also known as the exploding cucumber, squirts its seeds out in a spray of goopy liquid at speeds around 44 miles per hour, allowing them to cross distances of about 32 feet from the source plant. How do they do it?? That’s the topic of a study this week that sought to expose the finer details of this impressive squirter.
“We study the remarkable seed dispersal mechanism of Ecballium elaterium, commonly known as the squirting cucumber, one of the most rapid motions in the plant kingdom,” said researchers led by Finn Box of the University of Manchester. “Despite its apparent simplicity, the specifics of the seed ejection process—combining mechanical, hydraulic, and ballistic phenomena—remain largely unexplored.”
“By integrating experiments, high-speed videography, and advanced mathematical modeling, we uncover unique facets of this strategy, including an unusual decrease in fruit volume prior to ejection which stiffens the stem and orients the fruit to an improved angle for dispersal.”
When Charles Darwin wrote that “endless forms most beautiful and most wonderful have been, and are being, evolved,” he was definitely talking about exploding cucumbers.
Thanks for reading! See you next week.