Life on Earth is Old

Life on Earth began somewhere. Scientists think that there was one single ancestor, which they call LUCA (Last Universal Common Ancestor). This would have been a unicellular organism that eventually diverged to create every living thing we have today. And I mean everything, from tiny bacteria to blue whales. And LUCA began a long, long time ago.

About 530 million years ago, the Cambrian Explosion saw the major expansion of complex life. It’s been estimated that LUCA appeared 4 billion years ago, about 600 million years after Earth’s formation.

But one study pushes that arrival back to about 4.2 billion years ago. It also indicated fascinating details of what life for LUCA might have been like.

To find exactly when life appeared on Earth, scientists had to work backward. They first compared genes in species living today and counted the number of mutations that have occurred since the common ancestor. Using a genetic equation, they worked out that LUCA must have existed as early as 400 million years after the planet’s creation. That would put his organism in the middle of the Hadean Eon, which was a hellish geologic nightmare. During this time, Earth experienced frequent collisions, including the one that created the moon. The surface was unstable, with lava bubbling to the surface.

The evolutionary history of genes is complicated. Scientists had to use complex evolutionary models to reconcile the history of genes with the genealogy of species.

The team also retraced the physiological characteristics of living species to discover what LUCA must have been like. Surprisingly, even though it was a unicellular organism, it appears to have had an immune system. This would indicate LUCA was already fighting off primordial viruses, which makes one wonder if viruses are truly alive.

While LUCA was exploiting and changing its environment, it’s likely it didn’t live alone. Its waste would have been eaten by other microbes such as methanogens, which produce methane as a by-product of their metabolism. Such arrangements might have created a recycling ecosystem.

Although this is the oldest common ancestor known, scientists don’t understand how life evolved from its very origins to the early communities that LUCA was part of.

 

https://www.msn.com/en-us/news/technology/all-life-on-earth-comes-from-one-single-ancestor-and-it-s-so-much-older-than-we-thought/ar-AA1So3MH?ocid=hpmsn&cvid=694052ebf2b54b488c496cce3ccd1493&ei=107

Million Year Old Skull

A digital reconstruction of a million-year-old skull could rewrite the human evolution timeline. That’s because, according to one study, the reconstruction suggests that humans may have diverged from our ancient ancestor 400,000 years earlier than thought. And that it happened in Asia, not Africa. The crushed skull was discovered in China in 1990. Labelled Yunxian 2, the skull was originally thought to belong to Homo erectus, a human forerunner.

The reconstruction revealed features closer to a species thought to exist later in human evolution. It bore similarities to Homo longi and Homo sapiens. However, the findings are likely to be disputed.

If true, then 1 million years ago, our ancestors had already split into distinct groups. The researchers tested their procedures again and again and are now confident about the result. If they are correct, there were much earlier members of various hominins, including Neanderthals and Homo sapiens.

It also upends the assumption that early humans dispersed from Africa. It appears that east Asia may play a key role in hominin evolution.

The research used advanced CT scanning, structure light imaging, and virtual reconstruction techniques. The results were printed on a 3D printer. The researchers relied on another similar skull to shape their model, then compared it to more than 100 other specimens. The results show a combination of traits, some of which resembled Homo erectus. But its larger brain capacity is reminiscent of Homo longi and Homo sapiens.

Some scientists not associated with the study are skeptical of the stated results, for various reasons. Others say the conclusions were plausible, but more evidence was needed.

 

https://www.msn.com/en-us/news/technology/million-year-old-skull-could-rewrite-human-evolution-timeline/ar-AA1Nn6Am?ocid=hpmsn&cvid=68e54e7fa73a4dc2b7bc8fbc2031cc2a&ei=56

World’s Most Armored Dinosaur

It was the world’s most armored dinosaur, until evolution did something strange.

Fossils found in Morocco have revealed that the armored body of Spicomellus was also covered in bone spikes that reached nearly a meter in length. The preserved remains are dated to more than 165 million years ago. They also show that the animal lost some of its armor as it evolved.

Spicomellus had a multitude of plates and spikes all over its body. These included meter-long neck spikes, huge spikes projecting upwards over the hips, and a range of long, blade-like spikes.

Spicomellus was a type of ankylosaur, which were heavily armored herbivores with bony skins similar to turtles. They lived from the Middle Jurassic to the Late Cretaceous period but went extinct 66 million years ago when a comet wiped out most dinosaurs.

Sometimes described as ‘walking coffee tables’, ankylosaurs were four-legged, squat and under 10 feet in length.

Usually, species become better at defending themselves over time. But this discovery showed that ankylosaurs lost some of their protection, despite their environment being more dangerous in the Cretaceous period. This particular fossil is the oldest known ankylosaur. Scientists thought that later species might have inherited similar features, but they didn’t. Therefore, experts believe the fearsome variety of spikes may have actually been used for attracting mates and showing off to rivals rather than for defense.

In later species, the spikes are gone, having been replaced by flat plates, which were likely used only for defense. The scientists speculate that as larger and more fearsome predators evolved, ankylosaur armor became simpler, less showy, and more defensive. This suggests they wanted to draw less attention to themselves.

The end of Spicomellus’ tail hasn’t been found, but some of the vertebrae have been fused together, which suggests it had a club or similar tail weapon.

 

https://www.msn.com/en-us/news/technology/this-was-world-s-most-armoured-dinosaur-then-evolution-did-something-strange/ar-AA1LkPbP?ocid=hpmsn&cvid=9c063d459322482f930a164f96dd0e06&ei=68

The Tree of Life’s First Branch

There was one common ancestor for all animals on Earth. If you trace the history of any creature—from humans to slugs—you’d eventually follow all the branches of the animal tree of life back to its trunk.

Coming from the other direction, that trunk had to branch off at some point, or we wouldn’t have a diverse collection of animals. Unfortunately, that first split has been elusive to scientists because it took place around 600 million years ago.

Scientists have figured out that the first split resulted in the birth of two creatures. One was the ancestor of almost all animals, while its “sister” gave rise to just one group of modern animals.

For decades, scientists have debated which group of animals came from the “sister” ancestor. They had two contenders—sea sponges and comb jellies. Thanks to new methods that enable researchers to analyze these animals’ chromosomes, they think they have the answer.

The key was to look not just at what genes each animal had, but where those genes were located on the chromosomes. As a creature evolves, chromosomes will rearrange, and genes will move around. But once genes move, it’s almost impossible for them to return to their original position. Therefore, whichever animal showed the least re-shuffling of genes on its chromosomes must have come into existence first. Out of the two options, whichever animal has the least shuffling is the sister.

The team compared the placements of certain groups of genes in sponges and comb jellies to the placements of those same groups in their closest single-cell non-animal relatives. (The single-cell relatives would have been closely related to the “trunk” organism and would have evidence of what that original genome looked like.) The closer an organism is to that genome, the less it has changed, and the more likely it is the sister.

In both the non-animals and the comb jellies, they found 14 groups of genes located on separate chromosomes. But in the sponges, they found those 14 groups were rearranged into 7 groups, which indicated they split from the original genome later than the comb jellies.

Consequently, the sister to all other animals, the first to branch off, and the most genetically isolated animal is the comb jelly.

Besides answering a long-standing biological question, scientists can investigate what this knowledge tells us about animal evolution, and the mechanisms of that evolution. And so the search for more answers continues.

Thank goodness they figured that out. I don’t think I could have remained sane another day without knowing which animal came first.

 

https://www.msn.com/en-us/news/technology/scientists-have-found-the-first-branch-on-the-tree-of-life/ar-AA1LAkS2?ocid=hpmsn&cvid=cddbc1e105374c51afa382b8cdd3674d&ei=18

The First Potatoes

The mystery of potato evolution has been solved—and it involved a tomato.

The potato is a global food staple. It was first cultivated thousands of years ago in the Andes of South America before it spread worldwide starting in the 16^th century. But its evolution has long been a puzzle, until a recent analysis finally unraveled its origins.

Scientists say that the potato lineage emerged approximately nine million years ago in South America, through a natural interbreeding event between a wild tomato plant and a potato-like species. This discovery is based on the genomic analysis of 450 cultivated types of potatoes and 56 wild species.

This ancient hybridization event led to the appearance of the potato plant’s distinctive tuber—the enlarged structure housing nutrients underground. While the edible part of a tomato plant is its fruit, the potato’s value lies in this subterranean growth. Researchers also identified two crucial genes involved in tuber formation, which deepens our understanding of this crop.

Potatoes are one of the most remarkable food staples, combining versatility, nutritional value, and cultural ubiquity. Around the world, people eat potatoes using virtually every cooking method. Although stereotyped as carbohydrates, potatoes offer vitamin C, potassium, fiber, and resistant starch. They are gluten-free, low-fat, and satiating. They are a nutrient-dense calorie source.

Resistant starch is a type of carbohydrate that resists digestion in the small intestine and ferments in the large intestine. This means it feeds beneficial bacteria in the gut.

The scientific name for modern a potato plant is Solanum tuberosum. Its two parents were ancestors of a potato-like species now found in Peru named Etuberosum (which closely resembles the potato plant but lacks a tuber) and the tomato plant. These two plants shared a common ancestor that lived about 14 million years ago, so they were able to interbreed when the hybridization event occurred five million years after they had diverged.

The hybridization led to genes being reshuffled so that the lineage produced tubers, which allowed these plants to expand into the cold, dry habitats of the rising Andes mountain chain. During the rapid uplift of the Andes, the potato plant could adapt to the changing environment and thrive in the harsh conditions of the mountains. The tubers stored nutrients for cold adaptation and enabled asexual reproduction to counter the reduced fertility in cold conditions. Therefore, the plant could survive and rapidly expand.

The study’s findings may improve cultivated potato breeding to address environmental challenges that crops presently face. There currently are roughly 5,000 potato varieties. Potatoes are the world’s third most important food crop for humans, after rice and wheat. China is the world’s leading potato producer.

It is hard to remove all harmful mutations in potato genomes when breeding, but this study may show how to make a potato free of harmful mutations using the tomato as the chassis of synthetic biology. It may also lead to a new crop species that would produce tomato fruit above ground and potato tubers below ground.

The potato and tomato belong to the nightshade family of flowering plants, which also includes tobacco and peppers, among others. The study did not investigate the evolution of other tuberous root crops that originated in South America such as the sweet potato and yuca, which belong to different families of flowering plants.

Although the parts of the tomato and potato plants that people eat are quite different, the plants are very similar. If you look at the flowers or leaves of these plants, they are very similar. And if you let your potato plant produce fruits, those fruits look like little green tomatoes. But don’t try to eat them; they are pretty yucky.

 

https://www.msn.com/en-us/news/technology/the-mystery-of-the-first-potatoes-has-finally-been-solved-and-a-tomato-was-involved/ar-AA1JJN5G?ocid=hpmsn&cvid=a1e7bc6999b149a6a70e4275bd5155de&ei=68

Back When Elephants Wore Coats

The Wooly Mammoth was one of the last mammoth species to become extinct. Its closest still-living relative is the Asian elephant. Mammoths used the Bering Land Bridge to migrate from Siberia to North America. Present day Alaska and Canada (and some of New England) were home to the Wooly mammoth, while another species, the Columbian mammoth, lived in the area covered today by the 48 mainland states, and as far south as Costa Rica. Recent DNA studies indicate that that Wooly mammoths and Columbian mammoths could and did impregnate each other.

The Woolly mammoth evolved in Siberia some 400,000 years ago. Some of them entered North America about 100,000 by crossing the Bering Land Bridge. I found several dates for extinction, such as 5,700 years ago in the Yukon (Canada), 5,600 years ago on St Paul Island (Alaska), 4,000 years ago on Wrangel Island (Russia), to 3,900 years ago on the Taymyr Peninsula (Russia). So yes, they co-existed with humans, who used mammoth bones and tusks for making art, tools, dwellings and as food.

Woolly mammoths are among the best studied prehistoric animal because of the discovery of frozen carcasses (Siberia & N America), as well as teeth, stomach contents, dung, and the depiction of them in prehistoric cave paintings. This species became known to Europeans in the 17th century, but had been known in Asia long before that.

Woolly mammoths were roughly the same size as modern African elephants. Males could reach shoulder heights of 11 ft and weighed up to 6 tons, while females reached a shoulder height of about 8 ft, and weighed up to 4 tons. A newborn calf weighed about 200 lbs, and would have been nursed for 3 years before being weaned to a diet of grasses and such. An individual could probably live for 60 years.

Well adapted to the cold ice age, the Woolly mammoth was covered in fur, which varied from dark to light. The ears and tail were short to minimize frostbite and heat loss. It had long, curved tusks, which it used for manipulating objects, fighting and foraging. Its diet was mainly grasses and sedges (a large family of flowering grass-like plants). Its habitat stretched across northern Eurasia and North America.

A genome project for the woolly mammoth was completed in 2015. It has been proposed that the species could be revived, but none of the methods proposed are yet feasible. One article I read postulated that reviving the species could possibly help stabilize the tundra areas of the far north, helping to mitigate the climate change those areas are experiencing, but their reasoning didn't make much sense to me. Having these large creatures roam through the thawing tundra, even if they drag seeds along with them, is not going to halt the thawing of the permafrost. The woolly mammoths could not survive when the rising temperatures melted the huge glaciers of the ice age, and I don't see how they would survive now, when the temperature is even higher.

In my opinion, bringing ice age critters back to life now would only be dooming them to a short, miserable existence before they once again go extinct.

 

https://en.wikipedia.org/wiki/Woolly_mammoth

Devonian Period

 The Devonian Period spanned about 60 million years of the Paleozoic, from 419.2 million years ago to 358.9 million years ago. It is sandwiched between the Silurian Period, which came earlier, and the Carboniferous Period, which is more recent.

The first significant  adaptations of life on dry land occurred during this period, for life was well underway in colonizing the land. Moss forests and bacterial/algal mats of earlier were joined early in the period by primitive rooted plants that created the first stable soils and harbored such arthropods as mites and scorpions. By far the largest land organism at the beginning of this period was a poorly-understood plant which was possibly the fruiting body of an enormous fungus, a rolled liverwort mat, or another organism of uncertain affinities. This plant stood more than 8 meters (26 ft) tall, which means it towered over the low, carpet-like vegetation that covered the land. The first fossils of insects appeared around 416 million years ago, in the Early Devonian.

Many Early Devonian plants did not have true roots or leaves like modern plants. These were generally very short, growing hardly more than a few centimeters tall. By the middle of the period, forests of shrub-like plants existed, for plants like horsetails and ferns had evolved. These had true roots and leaves, and many were quite tall. Also, the earliest-known trees appeared in the Middle Devonian, although probably not any that we would recognize. Certainly I didn't recognize them from their descriptions, and they all seemed to have 'extinct' in their description. By the end of the Devonian, the first seed-forming plants had appeared. There was such a rapid appearance of so many plant groups and growth forms that it is called the "Devonian Explosion". Various terrestrial arthropods (which includes insects, spiders, and crustaceans) also became well-established.

Fish reached substantial diversity, so that Devonian is often called the Age of Fishes. Among the marine vertebrates, jawless armored fish declined in diversity, while jawed fish increased in both the sea and fresh water. Early cartilaginous and bony fishes also became diverse in the seas. The first abundant genus of shark appeared during this period. The ancestors of all four-limbed vertebrates began adapting to walking on land, as their pectoral and pelvic fins evolved into legs.

The first ammonites (an extinct specie of mollusc) appeared during the Devonian. Trilobites (which look something like armored roaches), brachiopods (similar to a mollusc) and great coral reefs were common in the seas. The Late Devonian extinction, which started about 375 million years ago, affected marine line severely, killing off—among other things—all trilobites save for a few species.

The Devonian was relatively warm, and probably lacked any glaciers. For this reason, the sea level was high. The temperature gradient from the equator to the poles was not as large as it is today. The weather was also very arid, particularly along the equator. Surface temperature of the tropical seas was probably 86°F in the Early Devonian, but CO2 levels dropped steeply throughout the period, because the newly evolved forests drew carbon out of the atmosphere. By Mid-Devonian, there was a cooling of about 9°F. However, there is evidence that the temperature rose again in the Late Devonian, which may have contributed to the extinction event.

The geography was dominated by the supercontinent Gondwana to the south, Siberia to the north, and the early formation of Euramerica in between. It was a time of great tectonic activity, as Euramerica and Gondwana drew closer together. In the early Devonian, Laurentia and Baltica collided, forming Euramerica, which rotated into the natural dry zone along the Tropic of Capricorn (appromately 23.3° South of the equator). Then the plate of Euramerica and Gondwana started to meet, beginning to form the supercontinent Pangaea. This raised the northern Appalachian Mountains and formed the Caledonian Mountains in Great Britain and Scandinavia. The west coast of Euramerica was low lying, with deep silty embayments, river deltas and estuaries (found today in Idaho and Nevada). However, a volcanic island arc approached the west coast in the Late Devonian, and began to uplift that coast in a prelude to mountain-building that happened later.

Hey, we're getting somewhere! If trees and tall bushes could grow during this time period, then the soil must be decent, right? So maybe we could grow crops, so long as we bring our own seeds. And maybe we could set up a farm with some barnyard animals, too, like chicken, ducks, cows and goats. There's insects for the fowl to eat. Do you think cows and goats would eat horsetails and liverworts? Because the article didn't say anything about grasses. And as long as we don't go swimming in shark-filled waters, I think we'd be relatively safe.

 

https://en.wikipedia.org/wiki/Devonian

Silurian Period

After the Ordovician Period came the Silurian Period, lasting 24.6 million years, from 443.8 million years ago to 419.8 million years ago. It began approximately the same time as the major series of extinction events mentioned at the end of the Ordovician Period, when a large number of marine fauna were wiped out.

The Silurian saw wide-spread diversification of jawed fish as well as bony fish. Multi-cellular life also appeared on land as small plants similar to liverworts, hornworts, and mosses, which grew besides lakes, streams and coastlines. Invertebrate animals with an exoskeleton also found land during this time period. This includes insects, spiders and crustaceans. However, terrestrial life would not greatly diversify until later.

With the supercontinent Gondwana still covering much of the southern hemisphere, a large ocean occupied most of the northern half of the globe. High sea levels and relatively flat land (there were few significant mountain belts) produced a number of island chains, meaning there was a rich diversity of environmental settings.

What was left of Gondwana remained intact and continued to drift south, but there is evidence that the icecaps were less extensive than those of the late-Ordovician time period. The smaller continents of Avalonia, Baltica, and Laurentia drift together near the equator, starting the formation of a second supercontinent known as Euramerica.

When proto-Europe (Baltica) collided with proto-North America (Laurentia), the collision folded coastal areas from modern New York State through Europe and Greenland to Norway. At the end of the Silurian Period, sea levels dropped again, and the new mountain ranges were rapidly eroded.

The Silurian period enjoyed relatively stable and warm temperatures, in contrast with the extreme glaciations of the period before it, and the extreme heat that would follow it. Sea levels rose during the first half of this period, and fell during the second half.

Climate was warm because high CO₂ levels and warm shallow seas produced a greenhouse phase. Glaciers at the South Pole nearly disappeared entirely. There is strong evidence of a climate dominated by violent storms generated by warm sea surfaces.

The Silurian was the first period to have megafossils in the form of moss-like miniature forests along lakes and streams. The first fossil records of vascular plants (land plants with tissues that carry water and food) appeared in the second half of the Silurian period.

Fish reached considerable diversity. A diverse fauna of sea scorpions (some of them several meters in length) prowled the shallow Silurian seas of North America. Leeches made their appearance.

About the middle of the Silurian, the earliest-known animals fully adapted to terrestrial conditions appeared, including a millipede. There is also some evidence of predatory spiders and millipedes and centipedes. Predatory invertebrates indicate that simple food webs were in place that included prey animals. These may have included those who grazed on micro-organisms.

Yes, we are getting closer and closer modern Earth. That is what happens when you start at the beginning and work your way towards today. I'm still not seeing any fauna that would be worth hunting. Although a millipede several meters in length might have enough meat to make a stew. Is the ground fertile enough to grow carrots and potatoes to put in that stew? And just how bad did those storms get? Maybe I'll keep going before I try to colonize.

 

https://en.wikipedia.org/wiki/Silurian 

Tonian, Cryogenian, and Ediacaran Periods

Tonian Period

The first section of the Neoproterozoic Era is the Tonian Period. It lasted from 1,000 million years ago to 720 million years ago. The breakup of supercontinent Rodinia began around 900-850 million years ago.

The first large evolutionary radiation of organic microfossils occurred during the Tonian Period. This means a huge increase in diversity caused by a large rate of specialization. None of the examples in this article of evolutionary radiation were from the Tonian period, however, probably since it involved microfossils, which most lay people are not terribly familiar with.

So, Rodinia started breaking up, and microorganisms multiplied and diversified. It still sounds like a pretty barren place to me.

Cryogenian Period

The second geologic period of the Neoproterozoic Era was the Cryogenian Period, lasting from 720 to 635 million years ago. There were 2 ice ages during this period, the Sturtian and Marinoan Glaciations, which are said to be the greatest ice ages known on Earth. There is much debate over whether these glaciations covered the entire planet (Snowball Earth) or a band of open sea survived near the equator (Slushball Earth).

In any case, the Sturtian Glaciation lasted from 720 to 660 million years ago, while the Marinoan Glaciation ended at approximately 635 million years ago, although there was no indication when it began. Whenever it began, it was relatively short-lived when compared to the Sturtian.

Fossils of hard-shelled amoeba first appear during this period, as well as the oldest known fossils of sponges. Debate about how much the glaciation might have impacted biology rages on, with some suggesting that several species began during this period.

Me, I much prefer warmer climes.

Ediacaran Period

The end of the Era is marked by the Ediacaran Period, which lasted from 635 million years ago to 541 million years ago.

Fossils from the Ediacaran are sparse, as not a lot of hard-shelled animals had yet evolved. But there were multicellular organisms with specialized tissues. The most common types resemble segmented worms, fronds, disks, or immobile bags. Although Ediacara biota bear little resemblance to modern lifeforms, more than 100 genera have been described.

During this period, the moon was considerably closer, making the tides stronger and more rapid than they currently are. A day was about 21.9 hours long, meaning there were about 13.1 months per year, and approximately 400 days/year.

Okay, now we're getting somewhere. The place had worms and fronds, or at least lifeforms that looked like them. I was particularly pleased with the information about the days being shorter and the moon being closer. How long do you suppose it would take human colonists to get used to a 22-hour day instead of a 24-hour day?

 

https://en.wikipedia.org/wiki/Tonian#:~:text=The%20Tonian%20(from%20Greek%20%CF%84%CF%8C%CE%BD%CE%BF%CF%82,Mya%20(million%20years%20ago).&text=The%20Tonian%20is%20preceded%20by,and%20followed%20by%20the%20Cryogenian.

https://en.wikipedia.org/wiki/Evolutionary_radiation

https://en.wikipedia.org/wiki/Cryogenian#:~:text=The%20Cryogenian%20(%20%2Fkra%C9%AA,and%20followed%20by%20the%20Ediacaran.

https://en.wikipedia.org/wiki/Ediacaran

  

Rhynchosaurs

Imagine a reptilian pig with a hammerhead, no visible ears, and a parrot-like beak, and you'll have a pretty good mental picture of a rhynchosaur.

Rhynchosaurs were herbivores that in some fossil localities account for 40 to 60% of the specimens found, making them the most abundant plant eaters on land. They were reptiles with stocky bodies and a powerful beak.

Early forms were small, less than a meter long, and typically lizard-like in build. They had narrow, wedge-shaped skulls with a few small, blunt teeth for eating plants.

Later versions grew up to two meters in length. The skull in these later forms were short, broad and triangular, becoming much wider than long, giving them a somewhat hammer-head appearance, although the eyes were set close together, near the top of the beak. The broad skull accommodated powerful jaw muscles that enabled the rhynchosaurs to cut up tough plant material. The teeth were modified into broad tooth plates, and the lower jaw fit into a groove on the upper jaw, enabling the ‘cutting’ of plant fibers.

The hind feet were equipped with massive claws, presumably for digging up roots and tubers, although digging claws are usually found on the front feet. Like many animals of their time, they spread all across Pangea, and thus across the world.

And that seems to about all there is to say about the rhynchosaurs. They lived during the Triassic era (251 to 199 million years ago), dying out just before herbivore dinosaurs appeared.

I think I would have found rhynchosaurs terrifying, particularly the larger ones, even though they were basically reptilian cows or deer. Let’s face it, the larger ones were as long as a man is tall, and who’s to say they wouldn’t try munching on this new plant called human that invaded their space, even if it didn’t sit still like other plants?

What do you think? If you had a time machine, would you venture back to visit them up close and personal?

 

https://ucmp.berkeley.edu/taxa/verts/archosaurs/rhynchosauria.php

https://en.wikipedia.org/wiki/Rhynchosaur

Nimravs

I couldn’t help but look up Nimravidae; the name reminded me of ‘nimrods’, which of course have nothing to do with Nimravidae. Naturally, I didn’t know that until I looked it up.

The Nimravidae were a cat-like creature whose fossils have been found in North America and Eurasia. They are sometimes called ‘false saber-toothed cats’. They existed from about 40.4 million years ago to 7.2 million years ago, spanning some 33.2 million years.

It is thought that the ancestors of nimravids and cats diverged from a common ancestor about 50 million years ago. Nimravid diversity appears to have peaked about 28 million years ago before the family began a slow descent into extinction. This diversity was apparent in the size and shape of their teeth, as well as the size of the body. Some nimravidae were the size of modern lions, and they had various other smaller sizes down to the size of a small bobcat. Their legs and tails were proportionally shorter than those of true cats.

When nimravid first appeared, the global climate was warm and wet, but it trended cooler and drier shortly after that. This meant the lush forests were transforming to scrub and open woodland, where the nimravids flourished. North America and Asia were connected at the time, and they inhabited both. Europe was more of a cluster of islands rather than a continent at the time, but there must have been some land bridges, for the nimravids also found their way there.

Still later, the woodlands were replaced by savanna in North America and Asia, and the nimravids in those areas died out. Portions of humid forests continued in Europe for a time, but when those died out in the late Miocene, so did the rest of the nimravids.

One has to wonder if the saber-tooth tiger that Fred Flintstone put out of the house every evening was really a saber-tooth tiger or actually a nimravidae.

On second thought, there may be a tenuous connection between ‘nimrod’ and ‘nimravidae’. The dictionary tells me that ‘nimrod’ refers to a person who is good at hunting. As a carnivorous species, the nimravidae had to be good at hunting. Now I wonder if that influenced whoever named this family of creatures. Or what exactly does ‘nimravidae’ mean in whatever language they used to construct this name?

  

https://en.wikipedia.org/wiki/Nimravidae

https://www.britannica.com/animal/Nimravidae

Jonah in a Basilosaurus

Okay, probably not what happened, because we are talking about an extinct species here. Basilosaurus means “king lizard” and it is a genus of large, predatory, prehistoric whale, living from approximately 41.3 to 33.9 million years ago. It was first described in 1834, based on fossils found along the Gulf Coast of the US, along with a few fossils in the eastern US. It was thought to be a giant reptile, hence the -saurus ending to the name. They were later discovered to be an early marine mammal, but it was too late to change the name.

 Likewise, the genus Basilosaurus was something of a wastebasket for odds and ends of fossils that nobody thought belonged anywhere else. But most of those have been removed and placed in more correct classifications, leaving 2 species in this genus.

 Unlike modern whales, who swallow their food whole, the Basilosaurus had various types of teeth, such as canines and molars, so it probably chewed it food. It was the top predator of its environment, preying on sharks, large fish and other marine mammals, such as another early whale, the Dorudon, which seems to have been their predominant food source.

 At a size of 49-66 ft (15-20 m), Basilosaurus  is one of the largest known animals existing from 66 million to 15 million years ago. Basilosaurus Isis is  slightly smaller than Basilosaurus Cetoides by about 7 feet.

 Basilosaurus appear to be closely related to even-toed ungulates, such as giraffes and buffalo. Does that mean it was a land animal that reverted to living in the sea? I don’t know.

 It is not believed that Basilosaurus could produce high-frequency sound and echolocation, which some modern whales can do.

 Studies of a complete skeleton fossil as well as overlapping skeletal reconstruction indicate Basilosaurua had about 70 vertabrae. They were shaped much like eels, and probably moved much like eels as well, mostly at or near the ocean’s surface, as they do not appear to have had a method for diving.

 So, if a person by the name of Jonah had been at sea during the time period, I suppose he could have been eaten by a Basilosaurus. But living through being eaten would have been problematic, since the Basilosaurus would have chewed before swallowing

 Since these were marine mammals, I suppose their ancestors were land mammals that - for whatever reason - decided to return to the water. And other branches of the family went on to become giraffes and buffalo, among others? What a family tree!

 

 

https://en.wikipedia.org/wiki/Basilosaurus

Giraffe Evolution

I’ve known for some time that giraffes and okapi are related. But in looking up giraffe evolution, I’ve discovered that giraffes are also (distantly) related to pronghorns, deer, musk deer, cattle, goats, sheep, wildebeests, and antelope. What a wide-ranging family! However, the opaki are their closest relative, so close that a 7-million year old fossil had a neck that was a blending of a giraffe neck and an opaki neck.

Giraffe and opaki ancestors once roamed all of Eurasia, but in modern times, they are only found in Africa. Giraffes live in the savanna grasslands, while okapi live in the rain forest.

One possible early ancestor of giraffes is the Canthumeryx, which lived in Libya. No one is sure when it lived; guesses range from 25 million years ago to 14.3 million years ago. It was a medium-sized animal, slender and antelope-like.

About 15 million years ago, Giraffokeryx appeared in the Indian subcontinent. It may have resembled an okapi or a small giraffe. It showed some definite lengthening of the neck.

The Sivatherium ranged throughout Africa and to the Indian subcontinent about 1 million years ago, and may have gone extinct as recently at 8,000 years ago, as ancient rock paintings greatly resemble them. The picture of a reconstruction of one show a pair of horns that look rather like the horns of a Texas longhorn, but only about a foot long each. The neck wasn’t as long as a modern giraffe, and the spots are depicted as being not quite so regular. It stood 7.2 feet tall at the shoulder, with a total height of 9.8 ft and a body weight of up to half a ton. Its shoulders were very strong to support the neck muscles required to life the heavy skull.

There was another giraffe-type animal that ranged from India to Turkey called the Bramatherium, which was closely related to the Sivatherium.

The Shansitherium was a superficially moose- or antelope-like giraffe from the Shanxi province in China. They were closely related to the Samotherium, which was rather like a half-way point between a giraffe and an opaki, as far as size goes.

Giraffes have horns! They are actually called ossicones, being made of bone and covered in furry skin. Some of their ancestors had 2, like modern giraffes, and some had 4. Sometimes they stuck up, or stuck up and curved back, or maybe they stuck out vertically. The Sivatherium horns as I described looked like small longhorns, did not look to be covered in furry skin, but they also had a pair of ossicones above their eyes.

So, if I ever want to make up a giraffe-like alien creature, I now know there is plenty of leeway for using my imagination!

https://evolution-institute.org/how-giraffes-evolved-such-a-large-neck/

https://en.wikipedia.org/wiki/Giraffidae