555-million-year-old oceanic creatures share genes with today's humans, finds a new study.
- A new study finds genetic links between early oceanic animals and humans.
- The animals studied had no heads, skeletons, legs, or arms.
- The creatures were from the Ediacaran era, living about 555 million years ago.
Dickinsonia fossil, an animal from the Ediacaran era.
Credit: Mary Droser/UCR
Paleontologist Scott Evans looking for fossils in the Australian outback.
Credit: Droser Lab/UCR
Fossils of ancient creatures doing anything are rare. This one is absolutely unique.
- A new fossil from southern China shows a dinosaur incubating its eggs at the time of its death.
- The find sheds light on oviraptor eating and egg-tending behavior.
- The find will be the focus of further study for some time.
Credit: Zhao Chuang / PNSO<p> The fossil depicts a large dinosaur sitting on a clutch of at least 24 eggs in a manner not unlike that of a bird. At least seven of the eggs contain fossilized embryos with the skeletons of the unhatched <a href="https://en.wikipedia.org/wiki/Oviraptor" target="_blank">oviraptor</a>. The apparently late level of development of these eggs combined with the lack of sediment between the bones and the eggs suggests that the oviraptor may have been incubating its nest when it <a href="https://www.eurekalert.org/pub_releases/2021-03/scp-wfd030921.php" target="_blank">died</a>. </p><p>"Dinosaurs preserved on their nests are rare, and so are fossil embryos. This is the first time a non-avian dinosaur has been found, sitting on a nest of eggs that preserve embryos, in a single spectacular specimen," explains lead author Dr. Shundong Bi.</p><p>Co-author Dr. Matthew Lamanna also <a href="https://www.sciencealert.com/fossilized-dinosaur-found-brooding-on-a-nest-of-preserved-eggs-with-actual-embryos-inside" target="_blank" rel="noopener noreferrer">commented</a> on how rare and exciting this find is:</p><p>"This kind of discovery, in essence fossilized behavior, is the rarest of the rare in dinosaurs. Though a few adult oviraptorids have been found on nests of their eggs before, no embryos have ever been found inside those eggs. In the new specimen, the babies were almost ready to hatch, which tells us beyond a doubt that this oviraptorid had tended its nest for quite a long time. This dinosaur was a caring parent that ultimately gave its life while nurturing its young."</p>
The fossil in question, notice the open sections of the blue green eggs.
Credit: Shundong Bi<p>While this small pile of bones may not look impressive to you, it is a proverbial goldmine of information for paleontologists, shedding light on dinosaur behavior in ways that other fossils can't come close to.</p><p>The parent—it is not currently known if it was male or female—clearly had <a href="https://en.wikipedia.org/wiki/Gastrolith" target="_blank">gastroliths</a>, also called "stomach stones," in its abdominal region. Commonly consumed by animals to help grind foods they cannot fully process with their teeth, this find adds the oviraptor to the list of dinosaurs that used these stones as part of their <a href="https://www.sciencealert.com/fossilized-dinosaur-found-brooding-on-a-nest-of-preserved-eggs-with-actual-embryos-inside" target="_blank" rel="noopener noreferrer">digestion</a>.</p><p>The different development levels seen in the fossilized embryos imply that the eggs might not all have hatched at the same time. This is a known occurrence for some <a href="https://web.stanford.edu/group/stanfordbirds/text/essays/Brood_Reduction.html" target="_blank" rel="noopener noreferrer">birds</a>, but before now, it was thought that this evolutionary development occurred too late for any dinosaur nest to feature it.</p><p>The researchers also examined oxygen isotopes in the remains and discovered that the eggs must have been kept at high temperatures typical of the incubation process. This further suggests that the parent was incubating the eggs as a bird does and keeping them at a necessary temperature rather than merely protecting them from an external threat, as a crocodile <a href="https://www.sciencedirect.com/science/article/abs/pii/S2095927320307635?via%3Dihub" target="_blank" rel="noopener noreferrer">does</a>.</p><p>While finding a dinosaur sitting on some eggs might not be the most exciting example of an activity-depicting fossil there is, the information that scientists can gather from it on the birth, life, and potentially the death of these animals will make this find an important one for years to come.</p>
Their ear structures were not that different from ours.
- Neanderthals are emerging as having been much more advanced than previously suspected.
- Analysis of ear structures indicated by fossilized remains suggests they had everything they needed for understanding the subtleties of speech.
- The study also concludes that Neanderthals could produce the consonants required for a rich spoken language.
Long-standing questions<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTcwNzYwNS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0MTI4OTY1NX0.xg5rA6RdbPSDXtDMIqfoEXbhVNfjKcVzpuBJgk1Hazw/img.jpg?width=980" id="501b1" width="1440" height="953" data-rm-shortcode-id="f1839c28760f9b0924bebcbaba8afa1c" data-rm-shortcode-name="rebelmouse-image" />
Neanderthal reconstruction (right), 2014
Credit: Cesar Manso/Getty Images<p>"For decades, one of the central questions in human evolutionary studies has been whether the human form of communication, spoken language, was also present in any other species of human ancestor, especially the Neanderthals," says co-author <a href="https://carta.anthropogeny.org/users/juan-luis-arsuaga" target="_blank" rel="noopener noreferrer">Juan Luis Arsuaga</a>.</p><p>The key to answering these questions, say the researchers, has to do first with Neanderthals' physical ability to hear in the frequency ranges typically involved in speech. In addition, while it's known that these ancient people had the physiological capacity for producing vowel sounds, the new research adds consonants to the Neanderthal repertoire, greatly expanding the possibilities for conveying a wide variety of meaning through the production of more types of sounds.</p>
Neanderthal hearing<p>The authors made high-resolution CT scans of fossilized Neanderthal skulls—and skulls from some of their ancestors—found at <a href="https://whc.unesco.org/en/list/989/" target="_blank">UNESCO's archaeological site</a> in northern Spain's Atapuerca Mountains. These scans served as the basis for virtual 3D models of the fossils' ear structures. Similar models of modern human ear structures were also created for comparison purposes.</p><p>Auditory bioengineering software assessed the hearing capabilities of the models. The software is capable of identifying sensitivity to frequencies up to 5 kHz, the midrange and low-midrange frequencies at which <em>homo sapien</em> speech primarily occurs. (We can hear much higher and lower frequencies, but that's where speech lies.) </p><p>Of particular importance is the "occupied bandwidth," the frequency region of greatest sensitivity, and therefore the spectrum most capable of accommodating enough different audio signals to represent a multitude of meanings. The occupied bandwidth is considered a critical requirement for speech since being able to produce and hear many different sounds—and understand their many different meanings—is the cornerstone of efficient communication. </p><p>Compared to their ancestors, the Neanderthal models turned out to have better hearing in the 4-5 kHz range, making their hearing more comparable to our own. In addition, the Neanderthals were found to have a wider occupied bandwidth than their predecessors, again more closely resembling modern humans. </p><p>Lead author of the study Mercedes Conde-Valverde says, "This really is the key. The presence of similar hearing abilities, particularly the bandwidth, demonstrates that the Neanderthals possessed a communication system that was as complex and efficient as modern human speech."</p>
Consonants<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTcwNzYxMS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1NDkxNzQ1M30.SRvXBjmAt1gq3gu42-NXoR21JdH9l8pkSKXKvZhlEI8/img.jpg?width=980" id="f5501" width="1440" height="796" data-rm-shortcode-id="c4ddda03ad35ff244463d2ef2f0d7227" data-rm-shortcode-name="rebelmouse-image" />
Credit: sakura/Adobe Stock/Big Think<p>The study also suggests that Neanderthal vocalization were more advanced than previously thought. Says Quam: "Most previous studies of Neanderthal speech capacities focused on their ability to produce the main vowels in English spoken language."</p><p>However, he says, "One of the other interesting results from the study was the suggestion that Neanderthal speech likely included an increased use of consonants."</p><p>This is important, since "the use of consonants is a way to include more information in the vocal signal and it also separates human speech and language from the communication patterns in nearly all other primates. The fact that our study picked up on this is a really interesting aspect of the research and is a novel suggestion regarding the linguistic capacities in our fossil ancestors."</p>
Bottom line<p>The study concludes that Neanderthals had the physiological hardware to produce a complex range of vocalizations, and the ability to understand them through ear structures not very unlike our own. This fits neatly with other recent insights as to the sophistication of the Neanderthals, a people who now seem to have been developing an expansive set of advanced capabilities simultaneously.</p><p>The authors of the study have been investigating the Neanderthals for almost 20 years, and others have been at it even longer. The work continues, and the study's publication marks a significant milestone in the much longer journey.</p><p>"These results are particularly gratifying," says co-author <a href="http://orcid.org/0000-0002-1835-9199" target="_blank">Ignacio Martinez</a>. "We believe, after more than a century of research into this question, that we have provided a conclusive answer to the question of Neanderthal speech capacities."</p>
One million year old mammoth DNA more than doubles the previous record and suggests that even older genomes could be found.
- Scientists extracting DNA from mammoth teeth have set a new record for the oldest DNA ever sequenced.
- The new record holder may also be a member of a new species of mammoth, but that remains to be proven.
- The findings suggest that DNA as old as 2.6 million years old could be decoded.
Mammoth Molars<p> The DNA was taken from three sets of mammoth teeth discovered in Siberia in the 1970s. The three samples, named Krestovka, Adycha, and Chukochya, are too old for carbon dating techniques to be useful. Their ages were instead determined using methods such as <a href="https://en.wikipedia.org/wiki/Radiometric_dating" target="_blank" rel="noopener noreferrer">radiometric dating.</a> </p><p>Krestovka is the oldest of the three, dating back to about 1.1 or 1.2 million years ago. In addition to setting the record for the oldest animal to have DNA sequenced from it, Krestovka appears to be the first known example from a new lineage of mammoth. It seems to belong to another branch of the evolutionary tree that left no living decedents. However, some of its DNA also exists in the Colombian mammoth's genetics, which raises other questions.</p><p>While it is too soon to say that Krestovka is from a new mammoth species, the possibility is there. If it is, then it also suggests that the Columbia mammoth could be a hybrid species between this unknown branch and the woolly <a href="https://gizmodo.com/million-year-old-mammoth-teeth-contain-oldest-dna-ever-1846287115" target="_blank" rel="noopener noreferrer">mammoth</a>. This would be particularly exciting, as evidence for hybridization creating new species is rare.</p><p>Adycha dated back about one million years. It is thought to be a steppe mammoth, a larger, less hairy ancestor of the woolly mammoth. Steppe mammoths lived across Eurasia but were considered to be best suited for warmer climates than Siberia. Some of the DNA fragments also imply that adaptations for surviving in cooler temperatures, revealed in genes related to fat deposits, thermal regulation, and the circadian rhythm, appeared earlier in the evolutionary tree than previously thought. </p><p>Chukochya is the youngest of the three. Dated to some point between 500,000 and 800,000 years ago, it was an early example of a woolly mammoth. </p>
Why is this exciting, exactly?<iframe width="730" height="430" src="https://www.youtube.com/embed/gHbYJfwFgOU" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe><p> DNA breaks down fairly quickly in most environments. Exposure to bacteria, water, ultraviolet light, or enzymes breaks it down. Even in the permafrost, where conditions are more favorable, these factors slowly whittle away at the information until little is left. That makes this find so exciting — it is remarkable that this much information endured a million years in the <a href="https://www.nytimes.com/2021/02/17/science/DNA-mammoth.html" target="_blank" rel="noopener noreferrer">ground</a>. </p><p>The previous record-holder was the DNA of a 750,000-year-old horse found in the permafrost of the <a href="https://www.sciencemag.org/news/2013/06/700000-year-old-horse-becomes-oldest-creature-sequenced-genome" target="_blank" rel="noopener noreferrer">Yukon</a>. In principle, it is possible to find DNA as old as the oldest permafrost: 2.6 million years old. Protein sequences last longer; the current <a href="https://elifesciences.org/articles/17092" target="_blank" rel="noopener noreferrer">record holder</a> is dated back to 3.8 million years but reveal much less information.</p><p>While the DNA from these mammoth teeth was quite fragmented, modern technology made putting the pieces together possible. By comparing what remained with the DNA of elephants and younger mammoth samples, the scientists could isolate the fragments that were unique to the specimen.</p><p>Ludovic Orlando, the head of the team which held the previous record, expressed his <a href="https://www.sciencemag.org/news/2021/02/mammoth-molars-yield-oldest-dna-ever-sequenced" target="_blank" rel="noopener noreferrer">excitement</a> at losing it, "I love this paper. I have been waiting since 2013 [for] our world record for the oldest genome to be broken."</p>
So do these findings mean we’re getting mammoth clones?<iframe width="730" height="430" src="https://www.youtube.com/embed/8c-EWSmOgDc" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe><p> Not yet. As mentioned, these sequences are incomplete and damaged due to their age. The cloning of mammoths using more complete samples of their DNA is generally thought to be a bit <a href="https://www.washingtonpost.com/national/health-science/can-scientists-bring-mammoths-back-to-life-by-cloning/2015/02/06/2a825c8c-80ae-11e4-81fd-8c4814dfa9d7_story.html" target="_blank" rel="noopener noreferrer">unfeasible</a>. Even if it could be done, there is a question of what you'd do with the animal you've created. While some have suggested bringing the mammoths back and putting them in <a href="https://science.sciencemag.org/content/308/5723/796.1" target="_blank" rel="noopener noreferrer">Siberia</a>, the benefits of doing this remain unstated. </p><p>However, the findings shine a light on evolutionary paths previously unknown to us and prove that these methods can work on other samples, potentially including even older ones. </p><p> So, even if you're not going to see a cloned mammoth any time soon, you may see a better model of one at the natural history museum and a better picture of how life on Earth, including our species, changes over time in response to shifting environmental factors. It's a great takeaway from studying some old teeth.</p>
Scientists discover burrows of giant predator worms that lived on the seafloor 20 million years ago.
- Scientists in Taiwan find the lair of giant predator worms that inhabited the seafloor 20 million years ago.
- The worm is possibly related to the modern bobbit worm (Eunice aphroditois).
- The creatures can reach several meters in length and famously ambush their pray.
A three-dimensional model of the feeding behavior of Bobbit worms and the proposed formation of Pennichnus formosae.
Credit: Scientific Reports