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

Whale Ancestors

Where did whales come from? How did a fish evolve to become as large as a modern whale?

Actually, whales took a round-about route to evolve into today’s huge ocean creatures. They are actually descended from a land animal.

There are plenty of clues in a whale’s body and biology that their ancestors lived on land:

* They breathe air.

* They nurse their young with their own milk.

* Their paddle-shaped flippers encase hand bones with five ‘fingers’.

* As embryos, whales have tiny back limbs which disappear before birth.

It turns out that hippos are the closest living relatives of whales, but not their ancestors. Both hippos and whales evolved from four-legged, even-toed, hoofed ancestors that lived on land about 50 million years ago. The hippo’s ancestor stayed on land, but the whale ancestor—which was about the size of a goat—moved to the sea and evolved into swimming creatures over a period of about 8 million years, which is quite fast for evolutionary processes.

When fossils of gigantic ancient whales were first discovered, they were mistaken for dinosaur fossils and given the name Basilosaurus. But later, they were recognized as mammals. These prehistoric whales were more elongated than modern whales and had small back legs and front flippers. Their nostrils were situated halfway between the tip of the snout and the forehead. They had earbones just like those of modern whales. Therefore, Basilosaurus showed the link between whales and their terrestrial ancestor.

The current theory is this: That some land-living hoofed animals favoured the flavor of plants at the water’s edge. Eating them had the added advantage of allowing them to easily hide from danger in shallow water. Over time, their descendants spent more and more time in the water, possibly in an ancient estuary, and their bodies became adapted for swimming. The front legs became flippers. A thick layer of fat called blubber replaced their fur coats to keep them warm and streamlined. Their tails became bigger and stronger for powerful swimming, and their back legs shrunk. Their nostrils gradually moved to the top of their heads so that they could breathe easily without having to tilt their heads while swimming. As these creatures began to feed on a different diet, they lost their teeth in favor of a baleen filter method of feeding.

Between these articles, there was some disagreement about what whale ancestors ate. One stated that they favored plants found at the water’s edge. Another felt they ate small land animals and fish found close to shore. Neither article had any information on the teeth whale ancestors had, so their eating preferences seem pretty much up in the air.

So, what can we learn from this tale of whales? Be careful what and where you eat? Evolution is your friend? I find myself wondering if whales would ever come back out of the water, what would they evolve to then? Some version of a goat-sized, hoofed animal again? One of the articles did mention that occasionally, a whale comes along that does have vestigial back legs that are completely encased within their body. Therefore, it seems possible that back legs could make a comeback.

Come on, work with me here. If octopuses can come out of the ocean and become a terrestial bad guy, as some scientists seem to think, then surely whales can also emerge from the oceans. Given enough time to evolve.

 

https://us.whales.org/whales-dolphins/how-did-whales-evolve/

https://evolution.berkeley.edu/evolibrary/article/evograms_03

https://www.nhm.ac.uk/discover/when-whales-walked-on-four-legs.html

Velociraptors

Velociraptors lived about 75 to 71 million years ago. There are 2 known species, both from Mongolia. The second species was only discovered in 2008.

They were depicted in the Jurassic Park movie as swift bipedal reptiles with a long tail and an enlarged sickle-shaped claw on each hindfoot, 6 1/2 feet tall and weighing about 180 pounds. Not so, say the scientists. They were bipedal reptiles, they were fast, and they had the fearsome claw. But they also had feathers, and were actually the size of a turkey. The raptors depicted in the movie series were based on a related genus, because the script said they had to look suitably fierce.

Instead of being 6.5 feet tall, velociraptors were as much as 6.75 feet long, snout to tail tip. Scientific artistic renditions show a very long, feathered tail. They were about 1 ft 7 inches high at the hip and weighs about 33 lbs. Although bipedal, their body and tail were roughly parallel to the ground. Their forefeet were also feathered, but were too short to serve as wings.

Their skulls grew up to 10 in long. The jaws were lined with 26-28 widely-spaced, serrated teeth on each side, more strongly serrated on the back edge than the front.

Their hands were large, with 3 curved claws. However, the structure of the wrist bones forced the hands to be held with palms facing inwards and not downwards.

On their feet, the first toe was a small dewclaw, and the 2nd held the ferocious claw spoken about earlier, which could get 2.5 inches long along its outer edge. Only their 3rd and 4th toes were used in walking or running. Although some beliere their 2nd toe claw was used for disemboweling prey, tests have proven it was most likely used for stabbing and holding, to keep their prey from escaping.

If we’re going to compare fiction to fact, then we must consider the depiction in the Jurassic Park movies of velociraptors hunting in packs. Although there are some indications of other species in the family hunting in packs, there is little to no indication in the fossils of velociraptors doing it.

Most of the known velociraptor fossils have been found in current desserts, under conditions that indicate the locale at the time of their death was also arid and covered in sand dunes, or possibly a little less arid.

Now, my first thought about incorporating velociraptors in a story involves a comedy-ish story where a town in the desert is suddenly overrun by predatory turkeys, which turn out to be—according to the local Wise Guy—descendants from velociraptors, long thought extinct these millions of years. Of course, once the raptors ate up all the local cats, dogs, and chickens, they would necessarily start picking on larger prey... large dogs, wolves, goats... children? Alas, I don’t do horror, which is where this thought is quickly leading me. Anybody out there have any other ideas?

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

https://www.livescience.com/23922-velociraptor-facts.html

https://www.nhm.ac.uk/discover/velociraptor-facts.html

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

One Hump or Two?

A camel is an even-toed ungulate, which means it walks on 2 toes on each foot. They also have distinctive fatty deposits (humps) on the back. The Dromedary (94% of the world’s camel population) has 1 hump. The Bactrian camel (6% of the camel population) has 2 humps. The Wild Bactrian camel is a 3rd species and at less than 1% of the camel population, it is critically endangered. All of these camels are suited to a desert habitat. Except for the Wild Bactrian, camels have been domesticated for a long time, and have been a vital means of transport for passengers and cargo. As domesticated animals, they also provide food, such as milk and meat, and textiles via fiber and felt from hair.

 Sometimes the word camel is used in a wider sense, to include not only the Old World camels but also New World camelids (llama, alpaca, quanaco and the vicuna). These new world animals are technically camelids, not camels.

 Camels live an average of 40-50 years. An adult dromedary camel stands 6’1” at the shoulder and 7’1” at the hump, while Bactrian camels can be a foot taller. Camels can run in short bursts at 40 mph, and at a sustained speed of 25 mph. Dromedaries weight as much as 1,320 lbs, while Bactrians can get up to 2,200 lbs.

 The earliest known camel is called Protylopus and lived in North America 40 - 50 million years ago. It was about the size of a rabbit and lived in the open woodlands of what is now South Dakota. By 35 million years ago, it was the size of a goat and had many more traits similar to camels and llamas. Other ancient forms of camels or camelids were the Stenomylius and the long-necked Aepycamelus.

 The direct ancestor of modern camels (and perhaps of New World camelids as well) was Paracamelius, which existed 3 - 5 million years ago. It spread to South America via the Isthmus of Panama, and to the ‘Old World’ via the Bering Land Bridge. There have been surprising finds of fossil Paracamelius on Ellesmere Island (very much north of Canada and barely west of Greenland) which indicate the dromedary is descended from a larger, boreal browser whose hump may have evolved as an adaptation in a cold climate. This particular creature is estimated to have stood around 9 feet tall.

 Which just goes to show that given enough time, evolution can completely adapt to an environment that otherwise would kill the original animal.

  

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

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

Hadean Eon

Unless you have a degree in geology or paleontology or something similar, you are probably as confused by the various Ages, Eons and Periods that get named when you look anything up about the History of Earth. I decided to take a look at one of them, and see if I could get it figured out as to when it happened, what major events happened during it... that sort of thing.

So, I had a list of these names, and I picked one at random: the Hadean Eon.

Turns out, I had picked the very first of Earth’s Eons; it started with the formation of Earth about 4.6 billion years ago and ended approximately 4 billion years ago. Other names for it are the Priscoan Period and the Pre-Archean Eon.

Obviously, since we are looking at the very first half billion years of the world, we won’t be talking about dinosaurs or super continents. What could there possibly be to discuss? Well, let’s dig in and see what turns up.

First, there’s the name, which gives us a clue about what was going on. ‘Hadean’ comes from Hades, the Greek god of the underworld. And that describes the conditions of what Earth was going through: The planet had just formed and it was very hot due to a number of factors, including frequent collisions with other Solar System bodies.

One important collision happened about 4.5 billion years ago, when a Mars-sized planetoid smashed into the infant Earth. The collision sent quite a lot of material into orbit around Earth, while the planetoid and the rest of Earth merged and tried to settle down. The orbiting material probably took less than a century to form the moon.

The big collision didn’t melt all of the Earth, but a fair fraction of material was vaporized, which created a rock vapor atmosphere around the young planet. But that rock vapor would have condensed out within 2,000 years, and left behind an atmosphere heavy in CO2 with some hydrogen and water vapor.

Apparently, there was a sizable quantity of water in the material that formed the Earth. After the moon was formed, the surface temperature was about 230C (446F), but even so, oceans of liquid water existed. That’s because the atmospheric pressure was over 27 times what it is today, because of the heavy CO2 atmosphere. As cooling continued, most of the CO2 was removed from the atmosphere by subduction and dissolving in ocean water, but the levels oscillated wildly.

One theory posits that between 4.4 and 4.1 billion years ago, the Earth’s climate was relatively cool, allowing for liquid water to be present at least that long. It was even suggested that the Earth may have been pretty much like it is today, except for the absence of flora and fauna.

One of the articles implied that life may have been getting started by the end of the Hadean Eon. But that was almost like a throw-away at the end of the last paragraph, so I’m thinking , one celled organisms? Maybe?

So as far as stories go, what if a spaceship gets too close to a forming star system and gets clobbered by tiny planetoids until it is forced to crash land on the nearest planet, which just happens to be vaguely Earth-like, but the only life it has are some quasi-amoebas swimming in the oceans. Maybe they have plants or seeds aboard, so they can grow some food. What about the stuff they don’t realize they’re carrying? Cockroaches, mice, fungal spores... What would those things evolve into, once there was enough food on the planet for them to successfully venture off the ship? There would be a whole lot of niches in the food chain for them to fill!

https://en.wikipedia.org/wiki/Giant-impact_hypothesis

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

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

Dinosaurs

Like most kids, I had a steady interest in dinosaurs when I was young. I never truly outgrew that interest, and the science magazines I read don’t have much to report on them very often. How disappointing. I long to learn all the new stuff they’ve learned since I was a kid. Can you imagine my surprise a few decades ago when I discovered Fred Flintstone’s powerhouse Brontosaurus never actually existed? It was the result of a few bones that did not necessarily belong together and a scientist’s active imagination while trying to put them together.

One of my school science projects was on dinosaurs. I bought several giant bars of Ivory soap and tried to carve them into various dinosaurs. The T-Rex didn’t want to stand up, the stegasaurus’ back plates were difficult to carve without breaking them off. The easiest to carve was the brontosaurus, which way back then still had a place on the dinosaur family tree.

I can’t do justice to dinosaurs in a few hundred words. After all, they were around - in one form or another - for millions of years. So I plan to look around, pick some interesting versions and report on them over the course of several months.

What do you think you know about dinosaurs? Were they all cold-blooded? Covered in reptile scales or simply skin similar to our own? Did they do any parenting of their young, or simply lay their eggs and move on through the countryside? Did they really evolve into birds? How big did they get? What was their smallest representative? Are there any ‘dinosaurs’ alive today, or maybe animals that look very similar to their ancient ancestors?

I remember a story - I don’t remember if I saw it visually or read it - where a group of hadrosaurs (That’s what I remember their type being, but I may be completely wrong.) had left Earth in some fashion back in the Long Ago, and established a home on another planet in another system. And now their descendants were space travelers and meeting humans in the vastness of space.

Wouldn’t that be something?

Well, since we’re approaching that point where we may be space traveling in a few generations (meaning, outside our home system), maybe we should be considering what evolved dinosaurs might be like. And to do that, we should start by learning what dinosaurs were actually like.

Any suggestions you want me to look at?

Cambrian Period

The Cambrian Period lasted from 541 to 485 million years ago. At the beginning of this time period, the small unicellulars that represented most life on Earth became more complex and multicellular. They also diversified quite rapidly, bringing forth the first representatives of all modern animal phyla. Indeed, there is strong evidence that all animals evolved from a single common ancestor.

Life prospered in the oceans, but the land is thought to have been relatively barren, with nothing more complex than a microbial soil crust or biofilm. A few molluscs may have emerged to browse on that biofilm, but the continents were probably dry and rocky. The global supercontinent Pannotia had just broken up during the early part of the period, and the new continents were mostly flanked by shallow seas, which were relatively warm. Polar ice was absent for much of this period.

Most land masses were clustered in the Southern Hemisphere during this period, but were drifting north. During the early portion of the Cambrian, the supercontinent of Gondwana went through some large, high-velocity rotational movements.

Trilobites (I wrote about them in an earlier post) were rampant during the Cambrian period. Possibly this was because without any sea ice, the sea level was high, which meant large areas of the continents were flooded in warm shallow seas, which is ideal for sea live. But the sea levels did fluctuate somewhat, suggesting there were ‘ice ages’, possibly meaning pulses of expansion and contraction of a south polar ice cap. Although the beginning of the period was cold, the average temperature during the Cambrian was 7° Celsius warmer than today.

Even so, trilobites were not the dominant species, as was once thought. It seemed they were, because they had hard external shells that were easy to fossilize, much easier than the thin chitinous shells of other arthropods, and so trilobite fossils were much easier to find by today’s paleontologists.

The Cambrian period is often referred to as ‘the Cambrian Explosion’, indicating a huge increase in the variety and diversity of life forms. But it seems (to me) that it might be better to think of it as ‘the Period of Great Changes’. At the start of the Cambrian, new creatures with new behaviors and lifestyles destroyed the biofilm that covered the sea floor, so all the creatures (from the previous time period) who depended on that biofilm died out.

Around 515 million years ago, the number of species dying out was larger than the number of new species coming into existence. 500 million years ago, the oceans saw a big drop in the oxygen content, and at the same time, the level of toxic hydrogen sulfide increased. Either of these events alone could produce extinctions, so imagine what happened when they came in together.

Where would hydrogen sulfide have come from? There are a few ways nature makes it, including anerobic digestion by certain biofilms in the absence of oxygen. I can’t rule that one out, but I’m somewhat more inclined to ‘blame’ volcanoes, which also produce it, probably in larger quantities and certainly can do it in oceans. Also, the heat given off by the volcano(es) would tend to drive oxygen out of the water. So, was there a series of huge volcano events 500 million years ago? I don’t know. It seems possible.

And there we have the Cambrian period in a nutshell. No fascinating dinosaurs to study, but the thought of a spinning Gondwana certainly has my attention.

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

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

The Sky is Falling

If you follow me on facebook, you may have noticed that I have shared many articles on climate change and that I have started using the comment, “The Sky is Falling.”

It seemed more appropriate than saying, “The Boy Cried Wolf.” In that story, the boy is lying, only looking to introduce some excitement into his own life, without regard for the consequences.

Chicken Little, on the other hand, was telling the truth, as best he knew it. Something (a raindrop) had come down from the sky and hit him. He had never experienced anything like that before, so the logical conclusion was that something terrible was happening, the sky was falling! Chicken Little ran around the farmyard squawking his terrible news, trying to warn all the other farm critters.

Even that doesn’t exactly fit the problem of climate change. Chicken Little was very young and inexperienced. But it’s scientists who have been trying to warn the world’s population that the climate was changing far quicker than it should. They have lots of experience at studying climate and how it has changed in the past, and they have a pretty darn good idea where it’s headed.

In the past week, I have read several articles concerning the number and severity of heatwaves that have been happening around the world. Not only has the world been having more of them, not only have they broken records for daytime high temperatures, they’ve broken records for the highest low temperatures as well. That means that after a sweltering day, you don’t get much relief during the night, because the heat that has accumulated all day doesn’t dissipate fast enough.

I think Europe has already broken several summer records during a heatwave in June of this year. There’s no guarantee they won’t have another later this summer. Or this fall, or... whenever. A heatwave can happen at any time on the calendar, because it is a comparison between the present and what has been ‘normal’ previously.

The scientists don’t ‘think’ any particular place will start having a heatwave every year. But it could happen. After all, they wanted us to keep the warming of the Earth to 2°C or less. What are they saying now, that it’s officially reached a warming of 1.8°C? But in Europe, the temperatures reached +4 to +8°C over ‘normal’.

I don’t know about you, but I don’t get much done when the temperature gets to 95°F. I sure don’t want it to consistently reach 123°F. Or higher.

Maybe Chicken Little isn’t the best story for me to quote to try to get my point across, but it’s the one I can remember as the summer heat settles in. So I’ll keep squawking my warning and hope somebody is listening, because...

The sky is falling.

What the heck is Lagerstatte?

When I first read about fossils found in ‘Lagerstatte’, I thought it was the name of a place or region, probably in Germany, that had a plethora of fossils residing there. Everything I assumed was pretty correct, except it’s not a place or region, it is a type of place. It turns out that in German, ‘lager’ means ‘storage’ and ‘statte’ means ‘place’. What this word indicates these days is a particular type of sedimentary deposit with fossils of exceptional preservation. I mean, sometimes even the soft tissue has been preserved, which is pretty darned exceptional.

This may have happened when a carcass was buried in an anoxic (without oxygen) environment with minimal bacteria, which would have delayed the decomposition of all biological features until a durable impression was created in the surrounding mud or whatever.

There are 2 types of Lagerstatte beds. The concentration type holds a lot of disarticulated hard parts, such as bones. Invariably, the accumulation of bones without a lot of other sediment takes time, so this type displays a large time period.

The 2nd type is conservation Lagerstatte, which hold exceptional preservation of fossilized organism or traces. Each of these sites can provide answers to important moment in the evolution and history of life. It’s like a snapshot, allowing the viewer to see the entire animal, even what the skin was like. Or the texture of a feather or shape of a footprint, in the case of a trace.

My first thought after reading about lagerstatte was that the now-fossilized creature must have fallen into water or mud, but there is oxygen in water (and thus in mud also), so that would not necessarily provide an anoxic condition. Still, there were places for them to land in order to be truly well-preserved.

Several types of inorganic replacement of the organic remains were mentioned in my reading; phosphorus, silica, pyrite (iron) and microbial mats. But in all these cases, this chemical change happened underwater. And if I read things rightly, under seawater.

The articles did have some pictures of these fossils, but they weren’t of T Rexes or stegosaurs, so I didn’t know what to look for. I gather that the large majority of these fossils are from way back when most creatures didn’t have bones, so they weren’t very large, and they hadn’t been well known before Lagerstatte beds were found.

I would have preferred to see one of these fossils first hand. Not to touch it, but when you have a picture, you can’t change the angle of how the light hits it and bounces into your eye. Sometimes just changing the angle a little can let you see details you otherwise wouldn’t notice. So I feel like having the item in front of me - even if in a display case - would let me study the tiny nuances that make these discoveries so exciting for those in the field.

Now, how could I use this knowledge in my writing? I don’t know. One of the beauties of writing fiction is that you get to use bits and pieces of knowledge in unimagined ways. So now that I have this knowledge, I can look for ways to use it.

https://en.wikipedia.org/wiki/Lagerst%C3%A4tte

http://www.fossilmuseum.net/fossilrecord/Lagerstatte.htm

Just Another Sink Hole

When you live in Florida, you get used to hearing about sink holes. When one opens up, it is filled with sand and rocks and everyone hopes it doesn’t continue to cause problems, especially if it occurred in a road. Before we moved here, I occasionally heard about a sink hole opening in other places, and they always seemed to swallow a car or two. But sink holes can be fickle things; some start out small and continue to grow until they are huge. Some seem to be bottomless pits that refuse to be filled, no matter how much sand and rocks are thrown into them.

Recently, I heard about a ‘sink hole’ in northern Wyoming, near the base of the Bighorn Mountains. Called Natural Trap Cave, it was discovered in 1970, when it was believed to be some 25,000 years old. Theory says that it opened up alongside a migratory trail used by many species, and they just kept falling in.

Located in a National Park, the sinkhole is 15 feet wide and (currently) 85 feet deep. Chances are that once an animal fell in, it wasn’t getting back out again. When it was first discovered, there was some digging of the bottom of the hole for a few years before it was closed up and left alone. In 2014, a new batch of scientists returned to do some more digging. They were only there for 2 weeks during August of that year, and before they could dig, they had to figure out how to safely get themselves and their gear to the bottom and up again. But what they found when they did get there was stunning; North American lions and American cheetahs, both of which went extinct about 12,000 years ago. During the 70s, scientists had discovered mammoths, short-faced bears, giant camels, and collared lemmings in the pit. Also discovered (but I’m not sure when) were dire wolves, tiny rodents that need to be studied by microscope, bison, grey wolves and horses.

Even though it was August, the scientists reported the hole was like a refrigerator. So much so that some of the skeletons still include DNA, so there will be huge strides in our knowledge of prehistoric genetics.

The 2014 group of paleontologists planned to continue their excavations another 2 years. They estimated that the depth of the pile of dead creatures could be 33 feet, and the digs of the 70s and 2014 had barely scratched the surface. With that said, they thought the bottom of this heap might have animals 100,000 years old.

If that turns out to be true, then this sink hole can’t be only 25,000 years old. That would make this one great, great grand-pappy of a sink hole. And amazingly stable for a sink hole, too.

http://www.telegraph.co.uk/news/worldnews/northamerica/usa/11026162/Hundreds-of-Ice-Age-fossils-found-in-ancient-sinkhole-in-Wyoming.html

http://westerndigs.org/wyoming-cave-yields-a-trove-of-ice-age-fossils-and-ancient-animal-dna/

http://www.ibtimes.com/25000-year-old-sinkhole-wyoming-treasure-trove-ice-age-fossils-1655030

https://weather.com/science/news/wyoming-cave-dig-reveals-hundreds-ice-age-fossils-20140809

Unique Argentina Dino

Sometime around 2012, an Argentina rancher found an old bone sticking up out of the dirt. Intrigued, he scratched around, trying to dig it up, then contacted paleontologists at the local museum to come see what he had.

He had found some big bones. And when the paleontologists dug around, they discovered the remains of 6 of the biggest titanosaurs ever discovered.

Titanosaurs lived about 100 million years ago, on all the continents, including Antarctica, which was not covered in snow and ice, and may or may not have been located at the south pole at the time. The ‘Titans’ were herbivores. The most complete skeleton was for a young adult some 122 feet long (its neck was 39 feet) and weighing 70 tons (about the same weight as 10 modern African elephants). One of the femurs uncovered was 8 feet long; long enough to be a living room sofa, if it were more comfortable to sit on. How big would it have gotten when it was fully grown? How did it get that big? And what kind of creature - if any - could consider one of these dinner?

As I stated, there were (at least) 6 individuals found at this dig site, which at the time these Titans died, would have been the flood plain of a river. ALL of them were young adults. But they didn’t die as one group; there were at least 3 separate events that took lives, which may have been a few years to centuries apart. A theory is that the youngsters got separated from their herd and died from stress and hunger.

https://www.nytimes.com/2016/01/19/science/titanosaur-argentina-american-museum-of-natural-history.html

Tyra

 I thought I’d take a look at Tyrannosaurus Rex. We all remember Tyra, right? Always represented as having a mighty roar and sharp, pointy teeth, and teeny, tiny forearms that wouldn’t even reach its mouth. Why would it evolve with such useless arms?

The first thing I discovered was that those tiny arms were quite strong, and each ‘hand’ had 2 sharp claws. So in a fight, if its mouth was already full of opponent, or it was still looking for the chance to sink its teeth into an opponent, those claws could be used to protect its belly, maybe? Well, not its abdomen, but the chest area. Any attack below that would call for leg action, either to stab or slice with its bigger foot claws, or to back up and get those fearsome teeth involved.

Other uses for these arms have been suggested; that they were used to grasp the female during sex, or that they assisted Tyra in rising from resting on the ground. Or from falling down, or being knocked down, or whatever. But one suggestion is actually supported by biomechanical analysis, and that is that the arms held Tyra’s struggling prey as the teeth did the work of killing it. Those arms are almost always shown bent at the elbow and held close to the body. And there’s a reason for that; Tyra’s shoulders could only move 40°, and its elbow only moved a maximum of 45°. So, no charades or sign language for this creature! To help you think about that, a healthy human shoulder can move 360°, while the elbow allows 165° of movement.

I had trouble picturing these restrictions. If you want, try this: Hold your arm down along your body and bend your elbow to make the forearm perpendicular to your body. This is your starting position. Now, keeping the elbow stiff in that position, raise your upper arm to not quite half-way to being perpendicular to your body. That is about how much Tyra’s shoulder could move. Now, extend your forearm to halfway between where it is and it being straight at the elbow. Imagine all the things you and I would not be able to do if that was all the further we could move those joints!

Okay, so these tiny arms may have been somewhat useful, but why did they evolve that way? What were Tyra’s ancestors like? And are there any descendants still around?

It was hard to find anything definitive about ancestors. The family tree that includes Tyra has many branches in that same time period, and they all seemed to have ‘stunted’ arms. A recent discovery from an earlier epoch held an almost complete skeleton of a very similar creature, possibly an ancestor of Tyra and/or other branches of that family tree. That article did not include much description - only that it was ‘horse-sized’ compared to Tyra’s ‘elephant-size - but the ‘artist’s rendering’ showed that ancestor as a skinnier Tyra, with somewhat longer and looser arms. That article stated that the ancestor already had a big brain, keen eye-sight, and sharp hearing at lower frequencies, and deduced that the Tyra family had developed these ‘smarts’ before it developed the brawn.

And of course, when the meteor hit and killed almost all the herbivores, a few Tyras - out of sheer desperation - shed over 99% of their weight, sprouted feathers and became birds. No, not really. When the herbivores died, Tyra’s family tree died, too. But some distant relatives - the maniraptoriformes family - did live on, and some of those did develop into modern birds. Which is good, because those tiny, practically frozen arms of the Tyra family were not going to launch a Tyra into the air, no matter how many feathers it had!

And now I’ll be shoving all this information into the grist mill that is my day-dreaming mind. Perhaps, on another planet, the end of the dinosaurs did not happen quite so fast, and the Tyras did manage to slim down and learn to fly. What do you think? Some kind of bird? Or dragon? Or something else entirely?

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

http://www.abc.net.au/news/science/2016-03-16/pregnant-t-rex-discovery-sheds-light-on-evolution-of-egg-laying/7251466

http://www.abc.net.au/news/2016-03-15/t-rex-tiny-ancestor-could-hold-clue-to-predator-dominance/7246928

The Malagasy Dinosaur

When I first read the name Malagasy Dinosaur, my eyes rearranged the letters and I thought I had read “Madagascar Dinosaur”. Then I thought, Of course not. Madagascar isn’t big enough to have had a population of dinosaurs.

Well, it turns out Madagascar is big enough. I guess you can’t judge a place by how it looks on a map. Especially not when it’s snuggled up next to a continent as big as Africa.

Madagascar is an island, and it’s believed it separated from the super-continent Gondwana about 85 million years ago. It has plenty of wildlife of some pretty strange species, as evolution has worked to fill all the niches in the food chain. Fossils found on Madagascar seem to indicate it’s had some strange species for a long, lo-o-ong time. Here’s some samples:

Beelzebofus antinga, an extinct frog that weighed up to five kilo (11 pounds). It is the heaviest extinct frog ever known. (Okay, not a dinosaur, but still…) If they were still around, maybe they’d be raised as food, like a chicken?

Rapetosaurus krausei was a dinosaur that reached 15 meters (49 feet) in length. It walked on all 4 feet and had a small head on a very long neck. It was a vegetarian, so I suppose we’d only have to worry that it might step on us, if we’d been alive at the same time as it.

Rahonavis ostromi was about 50 cm (19-20 inches), wore feathers over its entire body, had claws, a long skull and a mouth full of sharp teeth. Could this be the ‘missing link’ between dinosaurs and birds?

Sinosuchus clarki looked somewhat like a modern crocodile. Kinda. Except it was less than 80 cm (32 inches) long, including a short, broad head and a short tail. It also had teeth perfect for grazing on plants, and bone plates under its skin to protect it from predators.

Speaking of crocodile-like dinosaurs, the Araripesuchus tsangatsangana looked a lot like modern crocodiles, except it had much longer legs.

But none of these interesting creatures were the one called the Malagasy dinosaur. Only the Majungasaurus crenatissimus bears that nick-name. The Malagasy looked similar to a Tyrannosaurus rex, except it only reached a length of 6 to 8 meters (19 to 26 feet) and probably only weighed a ton. Even though it was so much smaller than its cousins, scientists say it took 20 years to reach its full size, so it grew much more slowly than the others, also. They made that discovery by studying cross-sections of several bones from a nearly complete skeleton found in 2003. The bones had marks of annual growth, rather like trees have tree rings. Of course, some bones had marrow in the center, displacing the earliest years’ record of growth. Other bones were hollow, and many of the bones were carved in order to reduce the creature’s weight.

The Malagasy lived 66 to 70 million years ago. However, it seems to have links to dinosaurs in south Asia (India) and South America (Argentina). So, could it be that Madagascar clung to Gondwana longer than was thought?

http://www.madamagazine.com/en/die-dinosaurier-von-mahajanga/

https://www.msn.com/en-us/news/science/fearsome-malagasy-dinosaur-remained-a-pipsqueak-most-of-its-life/ar-AAksFEa

Ick! It’s an Ichthyosaur!

Ichthyosar means “fish reptile” in Greek. Fossils reveal that they appeared about 250 million years ago, and one branch lasted until 90 million years ago. Their ancestors were some unidentified land reptile that decided to return to the water and become fish-like, much like dolphins and whales.

Science became aware of ichthyosaurs in the early 1800s when the first complete skeleton fossil was discovered in England. Later that century, many more Ichy fossils were found in Germany, and some of them included soft tissue remains. (No longer soft, after being fossilized, of course.)

Ichys ranged from 1 meter to over 16. Some resembled modern fish, others looked more like dolphins. They had pointed heads and often pointed teeth. Some could and did attack large animals that wandered into reach. They had large eyes, probably so they could dive deep. Their legs had completely converted into flippers, although many species’ flippers had numerous digits and phalanges (bones of the digits). They were not really fish, because they breathed air, gave birth to live offspring (up to 11 at a time), and were warm-blooded.

Life as an ichy was not all hunting and reproducing. One fossil had bite marks on its snout, apparently from one of his own kind. The bites had started to heal, so it survived the attack, but was this common? Or had he/she really made someone angry? Another fossil was complete… except for its tail. The theory is that it was ambushed by another of the big ocean predators, which bit off its tail. That ichy – unable to swim – sank deeper, drowned, and eventually became a fossil.

At one of my jobs, they decided to install an aquarium. If you want a healthy aquarium, you need a bottom feeder, usually a catfish. The fish they got included a bottom feeder, probably some type of catfish, but I thought it was ugly; flat bottom, thick whiskers, brown with black spots on skin that looked slightly fuzzy. I wound up calling it ‘Ichy’. I was familiar with the name, but didn’t realize they had all died out long ago. And since this fish didn’t actually look anything like an Ichthyosar, the name really didn’t fit.

I feel sorry for that poor bottom-feeder, now. I grew to rather like him, but I still called him ‘Icky’ (my pronunciation). It really wasn’t fair. I’m sure others of his species – whichever one he belonged to – thought him quite acceptable.

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