SoylentNews is people
SoylentNews
from the be-grateful-for-that-asteroid dept.
Submitted via IRC for Runaway1956
Post-apocalyptic fossils show rise of mammals after dinosaur demise
A revelatory cache of fossils dug up in central Colorado details as never before the rise of mammals from the post-apocalyptic landscape after an asteroid smacked Earth 66 million years ago and annihilated three-quarters of all species including the dinosaurs.
The fossils, described by scientists on Thursday, date from the first million years after the calamity and show that the surviving terrestrial mammalian and plant lineages rebounded with aplomb. Mammals, after 150 million years of subservience, attained dominance. Plant life diversified impressively.
With dinosaurs no longer eating them, mammals made quick evolutionary strides, assuming new forms and lifestyles and taking over ecological niches vacated by extinct competitors. Within 700,000 years of the mass extinction, their body mass had become 100 times bigger than the mammals living immediately after the mass extinction.
“Were it not for the asteroid, humans would never have evolved,” said Ian Miller, curator of paleobotany and director of earth and space sciences at the Denver Museum of Nature & Science. “One message I would like people to take from this is that their earliest ancestors - and by ancestors we’re talking fuzzy little squirrel-like critters - had their origins in the wake of the extinction of the dinosaurs.”
The thousands of well-preserved animal and plant fossils, unearthed just east of Colorado Springs, illuminate a time interval that had been shrouded in mystery.
“Essentially, we were able to tease out details of the emergence of the modern world - the age of mammals - from the ashes of the age of the dinosaurs,” Miller said.
Sixteen mammal species were discovered, with skulls and other bones fossilized after being buried in rivers and floodplains. Until now, only tiny mammal fossil fragments from that time had been discovered.
“For the first time, we were able link together time, fossil plants, fossil animals and temperature in one of the most critical intervals of Earth’s history,” said Tyler Lyson, the museum’s curator of vertebrate paleontology and lead author of the research published in the journal Science.
(Score: 2) by Hyperturtle on Tuesday November 12 2019, @02:35PM
I had sort of picked up over the course of my childhood and education that... Dinosaurs never recovered, and reptiles already were in abundance, thus leaving... mammals... as the new lifeform to rise to dominance after the dinosaurs reign had ended.
I never once thought that it played out a different way (even if I *have* played as the reptile faction in Total War II: Warhammer).
The rise of mammals had been described quite thoroughly, if perhaps only convincingly and not backed by factual data depicting the favored timeline of events. Back when I was a youngin', there was still debate about if climate change or sickness or volcanic or cosmic catastrophe ushered in the end of the dinosaur eras for good. It had already been determined that prior mass extinctions had to do with Earth-centric geological processes, such as oxygen depleting events or atmospheric poisoning (such as due to volcanism) leading to a similar demise, but recurrance of dinosaurs as the dominant species again, once they (and everything else) recovered from the event.
Even back then, it was (I thought) presumed that tiny mammals escaped into burrows or whatever to seek shelter/find food/otherwise survive in an environment where larger animals couldn't for a variety of pressures suddenly thrust upon them.
There'd even been fossils found back then, where dinosuars that looked like big chickens had been fossilized in their nests, splayed out over their eggs as if protecting them, which also were fossilized. Small rodent type mammals were even scavenging in the same area and fossils of small mammals frozen in their tracks also found in many similar nesting areas; this lead me to believe and agree with the whole giant impactor theory.
Nests or flocks of dinosaurs/reptiles don't get fossilized into river sediments while protecting their eggs and looking very much as if they were covered in concrete and left for millions of years -- it reminded me later (when I learned in high school about the human impacts natural catastrophes in ancient history had on civilizations) of how Pompeii's victims have been found--frozen in their last moments, sometimes cowering, sometimes trying to escape, sometimes in groups of the people and animals they died with.
It seemed very similar, but I'm not a geologist or paleontologist or anthropologist or grave robber or what have you. The whole dinosaur arguments about what killed them off just seemed like the competing theories made for better museum attendance, no matter the iridium levels found in the same rock layers etc... where places like Pompeii were very obviously destroyed by vengeful gods, right, so it was pretty clearly laid out as to what happened, despite the similarities in many of the 'fossilized' people and ancient fossils of dinosaurs that also were covered in volcanic ash and helplessly unable to avoid their fates.
Still, that recent timeline published (not related to this article) that describes the first few days of what happened after the meteor impact that made the big crater called the Gulf of Mexico.. was pretty interesting to read. One key description I recall was that it took a few hours for the sonic blast/shockwave to reach the farther ends of the Northern and Southern American continents. It came out of nowhere for the animals impacted, and likely explains how many such animals were frozen on their eggs trying to weakly defend them from world closing in around them.