A look at the past and present of this special biological process and the things that have changed

Significance of photosynthesis

Imagine a world without photosynthesis. There wouldn’t be any to begin with. It is not just the lifeline of plants but also all big and complex beings on the planet. Oxygen, the byproduct of this process casually discarded by plants, is the sole reason for Earth to be full of complex beings like us. It is required to release energy from food that is used to produce ATP that powers the cells; it is required by organic matter to decompose and return to the soil; it is involved in many metabolic processes that are essential to detoxify harmful substances; it prevents the planet from losing water, and after all of this, we need it in our atmosphere as ozone to absorb harmful ultraviolet radiation.

Mars is the closest to what we can imagine a world without oxygen. Barren, lifeless, and hopeless. There would be no long food chains, and life, though possible, would only be visible under a microscope.

The recipe

We are all familiar with the chemical reaction of photosynthesis from school days, where 6 molecules of carbon dioxide combine with 6 molecules of water in the presence of sunlight to create one molecule of glucose and 6 molecules of oxygen gas. But this was not always the case. In the distant past, bacteria used things like iron or hydrogen sulfide instead of water. But what is the significance of these ingredients? It has everything to do with the chloroplasts.

Chloroplasts are organelles in plants that contain two kinds of photosystems, PS I and PS II, and each photosystem has its role in a process called Z scheme. The function of these photosystems is to trap sunlight and produce sugar by utilizing quantum physics and chemistry. In PS II, when a photon hits the electron extracted from water by chloroplasts, a transfer of energy occurs, which vigor the electron to jump to a higher energy state and immediately return to its original energy orbital, releasing energy along the way used for producing ATP. In PS I, when a second photon hits the electron, it jumps again to a higher energy state and is transferred to carbon dioxide, starting the process of making sugar.

Although the process seems normal, two very strange things are happening here. Firstly, carbon dioxide is a very stable gas with a negative electron affinity, which means it does not readily accept electrons. This is only possible through the ATP produced during PS II and NADPH. Secondly and more importantly, water is a very stable compound that does not want to lose an electron. In the Z scheme, it is split into molecular oxygen, protons and electrons in the Oxygen Evolving Complex (OEC) of the chloroplasts, which we will discuss later.

Why shift to water?

Before cyanobacteria evolved to perform oxygenic photosynthesis (photosynthesis that releases oxygen), other types of bacteria used hydrogen sulfide to obtain free electrons. Some even oxidized iron in seawater, as both hydrogen sulfide and iron are better electron donors than water. So why did cyanobacteria switch from these conventional sources to water? Studies show that oxygenic photosynthesis evolved when hydrogen sulfide and iron were still abundant, so the change wasn’t due to a scarcity of these materials. It may have happened because water splitting has higher redox potential that oxidation of hydrogen sulphide, which means that more energy is released when electrons are extracted from water than from hydrogen sulphide.

The role of manganese

The evolution of chloroplasts to split water was a fascinating one. It involved an already existing biochemical process and made use of it. Manganese is a compound that bacteria welcome as they use it as an anti-oxidant. It catches ultraviolet light, throws an electron, and becomes oxidized, thus preventing the bacteria cells from harm. This method was incorporated by chloroplasts by developing an oxygen-evolving complex, as previously mentioned, which is a cluster of four manganese atoms and one calcium atom held together by a lattice of oxygen atoms.

Once the manganese atoms are oxidized, they combine their electron-accepting power to split water, thus providing a way to extract electrons. This process is further accelerated by the presence of chlorophyll, the pigment that is responsible for the green color of the leaves. And this is how the first bacteria evolved to use water and carbon dioxide to get energy.

These evolutions indicate that life always finds a way to thrive in any environment. The biological add-ons that cyanobacteria developed to use the most abundant thing around them is a reminder of life’s efficient approach to sustainability. It also highlights the relationship between the planet and the creatures that live on it. This innovation allowed the Earth to inject oxygen into its atmosphere so that further complex plants and animals could appear. And it would not be a hyperbole to say that the evolution of photosynthesis to use a precious liquid in place of toxic gas is the most important evolution in the history of Earth.

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The Evolution of Photosynthesis was originally published in Fossils et al. on Medium, where people are continuing the conversation by highlighting and responding to this story.

And why it is significant for paleontology

Choking on food is a common mishap, but picture this: a tiger, renowned for its carnivorous appetite, choking on a pumpkin. Sounds absurd, right? Similarly, imagine the surprise of paleontologists at Universität Hohenheim’s Staatliches Museum für Naturkunde Stuttgart when they unearthed fossils revealing an actinopterygian fish, Pachycormus macropterus, whose demise was caused by swallowing a sizable ammonite. It’s a prehistoric tragedy that not only showed the unexpected quirks of ancient life, but also opened new dimensions of understanding the ancient world.

Samuel L.A. Cooper and Erin E. Maxwell, the two paleontologists in Germany who found the fossils of these bony, ray fined fish along with a 10 centimeters wide ammonite fossil, estimated that this fish swam in the Jurassic waters nearly 180 million years ago. It was found at a site called the Posidonienschiefer Formation. What made this discovery remarkable, as these two researchers mentioned in their research paper, is the fact that prior to this, there was no direct evidence of a predator-prey relation between actinopterygians and ammonites, i.e. no ammonite remains had been found in the fish’s gut prior to this discovery.

There are two theories that have been put forward for the cause of death due to ingestion of this ammonite by the fish.

1. The sheer size of the ammonite may have posed a fatal obstruction, its shell may have stuck in the foregut, and in an ironic twist eventually led the fish to choke and drown.
2. If the shell was able to steer through the gut successfully, it may have cleaved the stomach wall, leading to internal bleeding. Alternatively, it may have choked the intestine, obstructing the passage of food.

Either way, researchers are sure that ingestion of the ammonite was directly responsible for the demise of this Pachycormus. This conclusion finds support in the observation of minor acid etching of the shell of the ammonite, indicating that it was ingested immediately before the death.

The absence of aptychi suggests that the ammonite was already deceased and decomposing at the time of ingestion. The gentle movement of its air-filled shell could have mimicked that of a small fish, potentially luring the Pachycormus. So it is possible that the fish had misidentified it to be the prey, or perhaps it may have been scavenging on the remains of this ammonite. After this fish died, it sank to the bottom of the ocean where it was buried in the mud.

The unearthing of these fossils was a stroke of luck for paleontologists, considering the typically unfavorable conditions for ammonite preservation in the area. Remarkably, this particular specimen stands out as an exception, retaining significant portions of its shell. It’s probable that the shell became sealed within the fish’s gut before burial, shielding it from further chemical dissolution. This fortunate circumstance offers a rare glimpse into the ancient marine world, shedding light on the intricate processes of fossilization and the serendipitous events that preserve glimpses of prehistoric life.

This discovery was the first confirmed case of an ammonite eaten by this now extinct pachycormid fish, and may indicate that ammonite feast was more common in the ancient world that was was estimated before.

Thank you for reading !

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The Fish That Choked On Ammonite was originally published in Fossils et al. on Medium, where people are continuing the conversation by highlighting and responding to this story.

The story of Thrinaxodon and how its study reveals a lot about the past and present of the mammalian world

250 million years ago, Earth was a vastly different place compared to its current state. It had already seen the horrors of three mass extinctions, the most recent being the end-Permian mass extinction that almost wiped out everything that breathed oxygen on Earth. What was left behind was the largest piece of land ever assembled, called Pangea. The inner parts of Pangea were hot and arid, particularly around the equator. Only those plants that could adapt to these conditions through deep roots and smaller leaves, like the conifers, could survive in these places. Life was tough for flora and fauna, and these tough times called for tougher survivors, those who could power through these difficulties and contribute to the evolution of mammals — and this led to the evolution of Thrinaxodons.

A detailed description of the end -Permian mass extinction can be found in the link below.

When the Earth Was Fed Up With Life: The End-Permian Mass Extinction

Discovery

Thrinaxodon was one of the cynodonts that emerged during the Early Triassic period. Its fossils were originally discovered in the Karoo basin of South Africa. They were described by Harry Govier Seeley, who made a separate genus for them and called them Thrinaxodon liorhinus. Thrinaxodon literally translates to ‘trident tooth’, which highlights the presence of trident shaped cusps on its teeth, that were unique in all the cynodont fossils that were found until then. Its specific name, liorhinus translates to ‘smooth nose’.

During the second half of the 20th century, its fossils were also discovered in Antarctica, suggesting that it was spread across the Pangean landscape instead of just being limited to the modern-day Karoo desert.

Lifestyle

Thrinaxodon was a small carnivore, no bigger than a fox. Unlike its diapsid cousins, its limbs were placed directly below its body. They were mostly straight, allowing for better movement than reptiles, who had to wriggle their bodies sideways, forcing them to compress one lung and expand the other one in the process, passing stale air between lungs instead of exhaling it out completely. Its body seems to have been covered in hair, which indicates that cynodonts had begun to develop warm-blooded bodies, as hair prevents the loss of body heat by trapping it. This adaptation allowed Thrinaxodon to become nocturnal, hunting at night and staying hidden in burrows during the day to avoid larger predators.

Beneath a night sky that would have hosted unfamiliar constellations to the human eyes, this creature hunted small herbivores and insects. Its jaws were powerful, a trait it inherited from the pelycosaurs, enabling stronger bites to crush the tough armors of insects. It had also developed teeth similar to those of mammals, which were used to chew food, making it one of the earliest animals to begin digestion in the mouth. Its body also developed a hard roof of the mouth, differentiating its mouth from the nasal passage and allowing it to breathe while eating, a privilege not extended to the reptilian ancestors.

Research indicates that Thrinaxodon likely exhibited minimal parental care for its offspring, as suggested by the very low survival rate of young ones after birth. Steve Brusatte, in his book ‘The Rise and Reign of Mammals’ suggests that Thrinaxodon may have had very short lifespans, probably being born, reaching adulthood, mating and dying within one year. This hypothesis is supported by the random patterns of collagen in its bones, indicating rapid growth.

Significance

Although Thrinaxodon disappeared from Earth during the late Triassic period about 200 million years ago, its fossils have proven to be a window for paleontologists to look into the past. The studies conducted on the fossils of Thrinaxodon have revealed remarkable developments in cynodonts, many of which were polished and incorporated by mammals. For example, the burrowing habits are still used by small mammals like rabbits to hide from predators and provide a safe nursery for their young ones.

It is hypothesized that Thrinaxodon and other nocturnal cynodonts developed excellent senses of smell and hearing, as they had to depend on these to hunt and avoid predators in the dark. Their eyes were also better adapted to see in the dark, which left little room for the development of eyes to see in broad daylight. We see all these features in today’s mammals (except humans) who roam in the wild. Even in our case, the pupils in the eyes dilate involuntarily in the dark to allow more light to enter the eyes, which is why we can see better after staying in the dark for a few minutes.

By studying the fossils of cynodonts before and after the end-Permian mass extinction, paleontologists found that the size of the cynodonts reduced after the event. This was called the ‘Lilliput effect’. Though the name may sound hilarious, this phenomenon of natural selection allowed cynodonts to outlive the gorgonopsians and dicynodonts during the extinction. This reduction in size allowed them to reduce predation risk, reduce the amount of resources needed to survive, and increase the reproduction rates.

Thrinaxodon not only survived but thrived during the Triassic period. Along with its other cynodont relatives, its fossils provide valuable insight into the early evolution of mammals and their emergence as a distinct branch in the tree of life.

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Trials and Triumphs of Our Ancient Relatives was originally published in Fossils et al. on Medium, where people are continuing the conversation by highlighting and responding to this story.

The new serpent king: Vasuki indicus

A major discovery of an ancient snake that could best the Titanoboa in length

The Limelight

Since its discovery in the early 2000s, paleontologists all around the world have been fascinated by the giant Titanoboa cerrejonensis, a 45 feet long and over 1000 kilograms snake that used to terrorize the tropical forests of South America around 60 million years ago. But recently, paleontologists working in the Indian state of Gujarat have been able to identify and describe another giant serpent through 27 well-preserved vertebrae (bones of the spine) recovered from the Panandhro Lignite Mine. The fossils were recovered around the same time as those of Titanoboa. Still, due to their massive size, scientists thought that they belonged to a crocodile and were left alone until 2022, when a research team of IIT Roorkee began re-examining the fossils. This snake was eventually named Vasuki indicus.

Nomenclature, Size, and Origin

The genus ‘Vasuki’ has been named after the mythical divine serpent in the Hindu religion, and rightly so, as this snake is estimated to be between 36 to 50 feet in length, which is longer than the Titanoboa (even though the vertebral dimensions of Vasuki is smaller than Titanoboa). Vasuki is a member of the extinct Madtsoiidae clade, and according to scientists, comparing it with other African madtsoiids reveals that they all had an Indian origin. It is a possibility that during the Eocene (around 50 million years ago), when India collided with Eurasia, these species spread to North Africa through Eurasia.

Behavior

Morphological studies of this snake have revealed some information about its habitat and hunting behavior. The vertebrae of Vasuki are transversely wide—meaning they are longer when measured side to side—which would have been associated with ribs placed sideways on the body. This suggests a broad and cylindrical body. It also suggests a non-aquatic lifestyle, as opposed to aquatic snakes that have transversely compressed vertebrae.

As mentioned earlier, the length of the vertebrae of Vasuki is small, and when combined with the snake's large size, it makes it unlikely they dwelled in trees. Also, because of its large size, it is highly unlikely that it used to live in burrows. Similarities between the vertebrae of Vasuki and modern pythons indicate a rectilinear locomotive motion and a terrestrial or semi-aquatic life. Additionally, it was too large to chase after prey actively and was most likely an ambush predator like anacondas.

An interesting diet

Now, this is interesting. Though not officially confirmed, this snake could have eaten whales! Not the modern day whales though, those are way to big even for Vasuki. We are talking about one of the earliest ancestors of modern-day whales, the Pakicetus. As the name suggests, this semi-aquatic animal was about the size of a wolf and lived in modern-day Pakistan. So it lived right where Vasuki existed and around the same time, 50 million years ago. Pakicetus may have spent more time in the deep sea to avoid this monster snake, and, over time, its lineage evolved into what we know as modern whales (the evolution was super fast; it took only 10 million years).

Why the large size

The uniquely large size of Vasuki indicus has been correlated with higher average temperatures during the Eocene epoch. During the late Paleocene and early Eocene, there was a period known as the Paleocene-Eocene Thermal Maximum (PETM around 55.8 million years ago), when the global temperature soared to about 30 degrees Celsius, triggering many major extinctions. And even though the global average temperature came down to 23 degrees Celsius during the middle Eocene (47 million years ago), the Earth was still warmer than today (the average global temperature today is about 17 degrees Celsius). An increase in temperature increases the metabolic rate in cold-blooded animals like snakes, allowing them to reach such sizes.

The discovery and description of Vasuki indicus make us wonder about the size and number of monster species of animals that have managed to escape the eyes of paleontologists until now. It also highlights the effect of the environment on the planet's living beings. The exact reason(s) for this snake's extinction is not known yet, as this is still a very recent discovery, but it may have something to do with climate change as well.

Thanks for reading!

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The new serpent king: Vasuki Indicus was originally published in Fossils et al. on Medium, where people are continuing the conversation by highlighting and responding to this story.

The most devastating mass extinction the Earth ever faced

The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.

— Carl Sagan

The above quote by Carl Sagan, the greatest science popularizer, describes the incredible importance of Earth for life. In many cultures worldwide, Nature has been given the title of ‘Mother,’ signifying that it gives us everything, doesn’t demand anything in return, and is crucial for birth. And for a large part of Earth’s history, that has been the case, except for the mass extinction events observed by fossil records across the globe. A mass extinction is most commonly defined as an event in history when at least half of the species on Earth go extinct within a million years. The Big Five mass extinctions, as they are known, have been time periods in which life has suffered the most, and these are:

1. The End-Ordovician Mass Extinction
2. The Late Devonian Mass Extinction
3. The End-Permian Mass Extinction
4. The End-Triassic Mass Extinction
5. The End-Cretaceous Mass Extinction

The star of the show

The most devastating of these is supposed to be the End-Permian mass extinction, which happened around 252 million years ago (which is sneaky because it sounds the least dangerous). What makes this event the most ferocious of all is the time scale in which it happened. As a reference, if we assume Earth's entire history to be a day long, the Permian mass extinction happened in a second! That’s it; all it took was a second (or 60k years) to wipe out more than 90 percent of the species on Earth. This was way faster than, for example, the Late Devonian mass extinction, which took around 15–20 million years. There is still a lot of debate over the cause of this extinction, and various scientists have put forward various theories in that regard.

Traces of a murder

But, to begin with, how do paleontologists figure out a mass extinction? They study the rock layers in the Earth’s crust to identify changes in fossils and then use isotopic dating techniques to age the layers of the rocks. Then, they also studied the fossil record before and after the probable time of extinction and checked how many species disappeared from the fossil record. In this case, chert also hinted at a possible mass extinction. Chert is a sedimentary rock whose primary component is silica. It is deposited on the sea floor when plankton in the seas absorb dissolved silica and die later. A lack of this chert, called chert gap, hinted at the insufficient number of sea organisms that may have stopped reproducing and, therefore, producing chert.

Another fossil record that strengthened the possibility of a mass extinction was the absence of coal deposits for about 10 million years during the late Permian. This called the coal gap, indicated that there was not much plant life in the world to contribute to the coal reserves. Then there is another slightly creepy and unconfirmed evidence that rivers at that time stopped their meandered flow because there were no trees left to divert the flow of rivers.

Life, just before death

The later part of the Permian period flourished with land and water life. At this time, all the continents of the Earth were combined into one supercontinent, called Pangaea, meaning ‘all of the land’. The land-dwelling therapsids and pelycosaurs have stolen all the limelight. Therapsids were the clade of animals from which mammals evolved. These included animals like the scary Inostrancevia, about 11 feet long. They were the rulers of the land; they hunted and ate whatever they liked. Then there was the Lystrosaurus, a pig-sized herbivorous animal. Dimetrodon were a species of pelycosaurs that were the dominant predators before Inostrancevia. I can best describe dimetrodons as lizards with sails on their backs. Most of these creatures were wiped out during the extinction.

The Permian Sea hosted Brachiopods, Ammonoids, Conodonts (which looked like aliens’ pet fish), Ichthyosaurs, and plankton, among other creatures. The conodonts and ichthyosaurs would survive this mass extinction only to be completely washed away during the end-Triassic mass extinction.

The suspects

What caused this mass extinction is still highly debated, and over the years, many convincing theories have been put forward after extensive study of this mass extinction.

The Siberian Traps — The Siberian Traps were a series of active volcanoes spanning over 2 million square kilometers in present-day Siberia. The eruption of these volcanoes is supposed to have covered miles and miles of land in thick lava. The greenhouse gases released in these eruptions are thought to have started warming the planet. The degree of this event can be understood by the fact that at present, about 40 gigatons of carbon dioxide are released into the atmosphere and water every year, while it is estimated that during this mass extinction, somewhere between 10,000 to 5,0000 gigatons were released. The current CO2 concentration in the atmosphere is 420 ppm. At the same time, according to some scientists, it may have reached 20 times that number during the end of Permian, and as a result, global temperatures shot up by more than 35 degrees Celsius.

As if the gases emitted by the volcanoes weren’t enough, the lava seeped into the Earth, igniting the coal reserves and releasing more greenhouse gases. These increased CO2 levels in the atmosphere caused the ocean water to lose oxygen, as in high temperatures water loses its ability to hold onto dissolved oxygen. Acid rains may also have killed a lot of plant life. Mercury, which is a toxic metal, was also released by the volcanoes, as was evident by the mutagenesis (genetic mutation) in surviving plants.

Rotten eggs — Or maybe something that smells like rotten eggs. Hydrogen sulfide, which is a gas at room temperature, is a highly poisonous gas. I distinctly remember its pungent smell during my high school lab experiment. At a concentration of 700 ppm, it can instantly kill a human. Scientists have discovered that along with the anoxic (less oxygen) conditions induced by high levels of carbon dioxide, there was a good amount of isorenieratene deposit at the time of the mass extinction. This is a compound produced by green sulfur bacteria that grows in anoxic conditions and requires hydrogen sulfide gas. Also, the abundance of fool’s gold (iron sulfide) attests to the presence of this toxic gas. Whether the levels of hydrogen sulfide were enough to choke terrestrial and aquatic life is debatable.

Ozone depletion—Ozone depletion is theorized to be another reason for this mass extinction. Researchers who studied the pollen fossil during the late Permian period indicate that some deformities arose from the pollen being exposed to UV light, which was supposed to be a result of the thinning of the ozone layer in the atmosphere. The cause of this depletion is supposed to be methyl bromide gas released during the volcanic eruption.

Methanogens — In a research paper titled “Methanogenic burst in the end-Permian carbon cycle,” the researchers argued that certain anaerobic microbes had acquired the pathways to create methane from acetate (a carbon compound), thus using increased carbon levels to survive. Their numbers grew rapidly, and so did the volume of methane, which is more dangerous than carbon dioxide as a greenhouse gas. This methane then increased the global temperatures, leading to the eventual extinction of life.

There are other less popular theories, like asteroid impact and interstellar dust, but scientists have debunked them.

The aftermath

Whatever the reason or group of reasons, one thing is clear: nature did not go easy on life on this planet for these 60000 years. Because it had such a bloodbath in such a short period, the Permian mass extinction is also known as the Great Dying. Life was hit so hard that it took another 10 million years to make a comeback, but it did, as it always has. The Earth cooled down in the aftermath of this mass extinction, and the first dinosaurs appeared. However, they were not as glorious and big as during the Cretaceous period and would have to live alongside mammals before becoming the absolute rulers of the planet.

I believe this mass extinction should be included in school textbooks to teach young kids about the hazards of exploiting the Earth’s resources and the impending dangers if sustainable development goals are unmet. The world once came together in Montreal to reverse the ozone hole by limiting the production and use of ozone-depleting substances; we can also save the planet from global warming.

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When the Earth Was Fed Up With Life: The End-Permian Mass Extinction was originally published in Fossils et al. on Medium, where people are continuing the conversation by highlighting and responding to this story.

Cool dinos — the Spinosaurus

The history behind its discovery and description

Ah! I have been dying to write about this. For most of us dinosaur fans, maybe the star of the show will always be the Tyrannosaurus rex, the icon of the Jurassic Park franchise and the most ferocious meat eater to ever live. But in some other part of the world, some 11,000 kilometers away from where the first T. rex fossils were found, scientists discovered something astounding: the remains of an animal that was going to change how dinosaurs were viewed.

In the twilight months of 1912, a search conducted in Egypt revealed what looked like long vertebrae. After a detailed inspection by German paleontologist Ernst Stromer, it was clear that these belonged to a totally new species. Further parts of its skull, jaws, and teeth helped scientists to reconstruct its shape in theory. This new species was eventually named Spinosaurus aegyptiacus (the spined lizard of Egypt), owing to the distinctive elongated spines found on its vertebrae, which gave it a unique appearance among theropod (meaning “beast-footed” and walking on two legs) dinosaurs. With a total length of over 45 feet, this was the largest carnivore ever to exist. Sadly, amidst the ongoing research, an Allied bombing of Germany during the Second World War destroyed the first described specimens (what we call the holotype) of this beautiful animal.

Due to the lack of fossils to study, the research on this dinosaur's biology, ecology, and evolution slowed down, and scientists began to give their theories based on the available knowledge. It was believed to have lived in the late Cretaceous period, some 98 million years ago. It was a semi-aquatic creature that lived near water bodies and hunted fish for food, as evidenced by the calcium deposits in its teeth. It had sharp claws that it used to skim the fish caught and a crocodile-like tail to help it swim. In early reconstructions of its body, it was thought to have looked like a proper theropod, but it was also thought to be capable of walking on all fours.

But life is known for giving everyone a second chance, and so it did to the fossil hunters when Nizar Ibrahim, a German-Moroccan paleontologist, visited the Moroccan Sahara and began searching for Spinosaurus fossils in a region famous for fossil excavation by local fossil hunters back in 2008. Nizar, who felt a close connection to Stromer because of his German roots, was determined to rediscover this dinosaur. Over the next four years, Nizar and his colleagues recovered many more parts of a skeleton. Once all these parts were prepared, computer simulations were performed to fill in the missing parts. A detailed reconstruction of the jaw and tail was made.

Through these reconstructions, some new remarkable facts were revealed. It was discovered that the Spinosaurus had smaller hind limbs than previously thought of, so it could not stand up like other theropods did. Some theories even suggested that it spent most of its time underwater, like crocodiles, but this is still debatable.

The huge sails on its back are supposed to serve display purposes to attract females. However, there is still so little known about this animal that nothing can be said for sure. One thing is certain: it was the apex predator in its region.

Why this absolute beast went extinct is a highly debated subject. Spinosaurus did not live at the end of the Cretaceous period, so the asteroid did not wipe it out. Scientists have proposed two possible reasons: climate change and competition.

The climate change theory — 90 million years ago, the Earth experienced a global warming event. Because of Earth's temperature change, the swamps Spinosaurus called home started converting into deserts. With the evaporation of water, the fish, which were its main food, disappeared. Because of this, Spinosaurus was slowly forced to go hunting on land, where it would face other theropods living in the region. Bite marks on the spines of a recovered fossil indicate that the specimen fought with another dinosaur, which may often have been fatal for it.

The competition theory—This theory takes into account the presence of large crocodylomorphs alongside Spinosaurus during its time on Earth. These crocodylomorphs were after the same food sources as the dinosaur, and being on the same turf, the competition led to Spinosaurus' eventual downfall.

We may never know what ended these dinosaurs, but it may be that the Spinosaurus was undoubtedly a gigantic predator, the likes of which the Earth has never seen since its extinction. It was the first known aquatic or semi-aquatic dinosaur. Its life on Earth also highlighted the devastating effects of various climatic changes that this planet went through in the past on life on Earth. It highlighted how the now dry and hot Sahara desert was once a wet swamp full of life. It also points out the fact that life is highly dependent on climate.

Perhaps there is no better quote to end this article than this one:

If we measured success by longevity, then dinosaurs must rank as the number one success story in the history of land life.

— Robert Baker

Published in Fossils et al. Follow to learn more about Paleontology and Evolution.

Cool dinos — the Spinosaurus was originally published in Fossils et al. on Medium, where people are continuing the conversation by highlighting and responding to this story.

We aren’t different from these animals, are we?

Through a tale of farm animals, told from the perspective of a nonchalant observer, Animal Farm captures the complexities of politics and subtly hints at few failed ideologies that are still practiced in the modern world. It is a story of an uprising, and how this uprising met its ultimate fate. The book talks about a farm, known as Manor Farm, whose owner Mr. Jones was known for his brutality by all animals of the farm, but they seemed too helpless to do anything about it, until one day an old pig, known as Major, collected all the animals for a meeting and started to talk about the “hell” that they were going through everyday. He suggested the animals to start a revolution, a revolution that would liberate all the animals of England from all the horrors.

After Major’s death, the rest of the farm animals decided to take forward his ideas of a safe and happy place for animals. As is the law of nature, it never penny-pinches in throwing opportunities when one really sets his/her eyes on a goal. The animals got one opportunity to get revenge on their master, and after a bloody battle, they had the farm all to themselves. They proudly renamed the farm “Animal Farm”, laid down seven commandments of the farm and even devised an anthem called “Beasts of England”. Meanwhile, the humans who heard of this news started spreading fake news about the farm, that the animals were in misery and the condition of the farm was worse.

Within a short time, the animals assumed their roles in the farm for smooth functioning. The pigs occupied the top spot, acting as the brain of the farm and ordering other animals around. They even learnt human language. This hierarchy went on successfully for a while, until Snowball and Napoleon, two leader pigs, got into a serious argument about building a windmill. At this point, Napoleon expels Snowball with the help of fierce dogs whom he took from their mother at the time of birth and raised all by himself. He declares that a windmill will be constructed, despite being totally opposed to the idea before. He laid out the duties and rations for each animal, making them work hard, while also using the threat of Jones’s return to blackmail them if they didn’t cooperate.

While the other animals toiled around the farm all day, Napoleon along with his companion Squealer started to misuse their power and periodically changed the commandments laid down earlier. For example, “No animal shall consume alcohol” was changed to “No animal shall consume alcohol in excess”, when the animals learned that the pigs were consuming litres of alcohol each day in the farmhouse.

The biggest blow to the founding principles of Animal Farm came when the pigs started trading with humans , who owned neighborhood farms. The hens, who had been told during the revolution, not to give their eggs to the humans, were now ordered to sell their eggs to humans in return for essential supplies for the farm. All this while, the mastermind of any tragedy that occurred on the farm was declared to be Snowball. At one point, the animals were so convinced of Snowball’s involvement, that they watched in silence as Napoleon’s dogs slaughtered any animal that was suspected to be Snowball’s spy.

The animals had to fight another battle from humans in order to keep their farm to themselves, while the pigs brainwashed them into thinking that Napoleon was their savior. They even sent Boxer, the horse, to a butcher when he was unable to work more, while tricking the animals into thinking that he was sent to a doctor.

This went on for a few years, and every now and then, the pigs changed the commandments while the other foolish animals watched and doubted their own memories. Finally one day, the pigs learnt to walk on two feet and the song “Four legs good, two legs bad” was changed to “Four legs good, two legs better”. The wall on which the seven commandments were written earlier, now contained only one commandment that read —

“All animals are equal, but some animals are more equal than others”

clearly implying that the pigs were superior to the others. The book comes to a close with the scene of the farm animals watching in bewilderment, through the windows of the farmhouse, the pigs playing cards with Mr. Pilkington and other humans while Napoleon declared to change the name of Animal Farm back to Manor Farm, arguing that it was the correct name. At this point, they were unable to distinguish between the pigs and the humans.

The book, very beautifully brings out the nature of people who wish to stay in power, and of the people who follow them. Orwell has incorporated every character that is found in the society-

The pigs, powerful and intelligent, who would go to any extent, even cheat their own kind in order to stay in power and enjoy most of the riches.

The dogs, bootlickers who would serve even the most corrupt individuals.

The horse, a foolish hard worker who did not care for his well being and was being taken advantage of everyday.

The sheep, who did not have much mental capability and accepted whatever they were told.

The donkey, who was wise enough to know what was happening before his eyes, but kept silent.

And at last, the mare, who ran away because of the greed for better food that was available elsewhere.

This book also describes how democracies decline, and military states trick their people into keeping them poor and uneducated. Overall, it was a worthy reading and I recommend it to everyone who is interested in social events and politics.

Thank you for reading !

If we look back at human history, we find that humans have been quite fond of creating art. The Neanderthals, for example, were the first to introduce cave paintings, depicting life stories of people, hunting, natural phenomena etc. It is hardly believable that those people would we doing such things to document their lives for future generations, many other priorities to think about. I believe what other historians believe, that the purpose of such art was just entertainment, to kill time when they were not killing animals (sorry for the bad joke).

Then after a few thousand years, singing and dancing came into existence when basic necessities like food, shelter and security were largely available to people living in tribes. The main purpose of the songs and dance was storytelling, to remember a heroic feat of a tribal chief, or to sing glory of a local god. Fast forward to the modern era, when movies and plays came into existence, their purpose was mass entertainment. I am a big fan of William Shakespeare’s plays, particularly “All’s well that ends well”, which beautifully shows the various emotions of society.

So these aspects — entertainment, storytelling and passtime were the primary reasons for the origin of art. But one may ask, was there ever a time where teachings were a part of art? The answer would be yes. In my country India, for example, epics like Ramayan and Mahabharat have been sung, written and performed for thousands of years, and were remembered and passed down verbally before the invention of paper and ink. Teachings like “good conquers the evil” were at the heart of these epics that also celebrated the greatness of hindu gods and goddesses.

Even Shakespeare in one of his plays “As you like it” writes a poem — “All the world’s a stage” that describes the various stages of human life and argues that human life is nothing but a theatre where everyone has to play their part. Children’s poems like “Old Mcdonald had a farm” that were written in the 18th century were aimed at educating young kids.

The advancement of internet and subsequently social media proved to be a catalyst of the merger of art and social reform. It helped to spread the word a lot faster and so connected a group of like minded individuals in a matter of hours. When we say something went “viral” on social media, it is nothing but a piece of art (videography, painting, photography, song etc.) that was shared, reacted to and commented upon more than usual, by a group identifying to a particular ideology.

In the present day, we rarely see any piece of art without any message. Be it the sand art on a beach, or an entire movie. This evolution of art has helped creators to push virtues like equality and justice into society.

“There is nothing more truly artistic than to love people.” — Vincent van Gogh

It has helped to promote thought provoking concerns around the world. It has also helped to give voice to people who were otherwise unheard.

However, the growing use of art for social commentary has created challenges of its own. Some artists try to create thought provoking art that ultimately becomes disturbing. The weaponization of art by negative political ideologies is becoming a trend around the globe. It is used by opposing political mindsets to push narratives. It is not a hidden fact that the results of much of the research work done in the world, are manipulated to benefit a group either economically or ideologically. Art is also set to go down the same path. The commercialization of art and ultimately of human suffering is another debate that goes on.

Furthermore, it has also created a social structure where going viral means everything to people, the so-called influencers. They would do anything to get views, cross any limit to get public attention, however negative it may be. Edgar Degas sums it up quite perfectly —

When I think we are stupid enough, we painters, to solicit those people’s compliments and to put ourselves into their hands! What shame! Should we even accept that they talk about our work?

It’s all about the satisfaction one gets after expressing oneself, rather than the number of times he/she is forwarded on whatsapp groups. The same is true for us writers.

The genuineness of art, the original purpose of mass entertainment and storytelling has become of secondary importance. It can also lead to desensitization of people towards social challenges in the future.

There is no doubt that our lives are empty without art. In conclusion, the prevalence of art with messages, both positive and negative, has become a defining characteristic of the contemporary artistic landscape. Artists have embraced their role as social commentators and activists, using their creative endeavors to advocate for change, challenge conventions, and shed light on crucial issues. While this has sparked meaningful conversations and increased awareness, the abundance of shocking and provocative art also raises questions about the impact on audiences and the true essence of artistic expression.

Thanks for reading ! Please comment your thoughts.

Astronomy is the study of heavenly bodies that are as close as the moon and as far as the end of the visible universe. From the day humanity evolved on the planet, we have been constantly curious and in awe of the little sparkling things above our heads at night. Stars, planets and the moon have been important parts in the survival and folklores of humans. Most of the admiration for the night sky comes simply from the fact that we are unable to know most of the things about the universe, even though it is right in front of our eyes. For any super-intelligent extragalactic being watching us from afar, we would seem like a cat who is watching a bowl of milk hung on the ceiling 15 feet above the ground, helpless and desperate.

Regardless, our ancestors made good use of these heavenly bodies for survival even if they didn’t know what those things were. Fore example, the helical rise of Sirius, the brightest star in the sky would alert the ancient Egyptians about the annual flooding of the Nile river. And of course, the pole star or Polaris, has been used by sailors for navigation for centuries. It is also recorded through cave painting studies that star and planet positions in the sky would be used by early humans to detect annual migration of animals, who were a source of food. Art was also influenced by outer space, after all who doesn’t recognize this iconic painting:

Needless to say, countless efforts have been made by astronomers to educate ourselves about outer space and beyond. One such significant study lead to the development of the iconic Hertzsprung-Russell diagram (or H-R diagram in short). The H-R diagram is a scatter plot that compares the luminosities of stars against their effective temperatures , and gives a distinct pattern which reflects the spectral class of the stars.

Let’s get familiar with a few important terms:

1. Luminosity : Broadly speaking, luminosity is the total energy (in the form of heat and light) that is radiated by a star per second. A star with higher luminosity will either higher effective temperature or bigger size.
2. Effective temperature : This is the temperature on the surface of a black body with the same luminosity as of the star.
3. Size : On the basis of their radii, stars have been classified into the following main categories :Dwarfs (red, white, brown), Main Sequence, Supergiants (red, blue) and Hypergiants(red, yellow, blue).
4. Spectral class : Each star is classified into a specific class (O,B,A,F,G,K,M) decreasingly based on their surface temperatures, O being the hottest and M being the coldest. There are subdivisions within each class, but we do not need that for building our diagram.

Under what spectral class do you think our sun falls into? Answer is in the end of this article.

Now with the theories clear, let’s move on to try to build the diagram ourselves. For this, we need a dataset of stars. The dataset that I used can be found here :

Star dataset to predict star types

Steps involved :

1. First I imported all the necessary python tools needed — like pandas, numpy and matplotlib. Loaded the dataset through read_csv().
2. Checked if the dataset contained any null values (it didn’t)
3. Assigned variables according to star types : R (red dwarf), W(white dwarf), B(brown dwarf), M(main sequence star), S(supergiant) and H(hypergiant)
4. Plotted a scatter plot with x axis as log(temperature) and y axis as log(luminosity)

The final scatter plot came out to be this :

This looks similar to the illustration shown earlier. We can clearly see the main sequence (which our sun is a part of), the white dwarf at the bottom, the supergiant and the hypergiants at the top.

After this I applied random forest classifier to train the model on identifying the spectral class of star based on its other data fields, that can be found here :

Star data analysis and prediction

About our sun, it is actually a G star , which means it is the third “coldest” in the spectral class of stars (so the next time you complain about the hot weather, just know that it could be a lot worse ;P)

Thank you for reading ! If you liked it, an upvote would be appreciated.

These were the words of Indian Prime Minister Narendra Modi when speaking about the national animal of India , the tiger. This statement shows that the country gave more weight to beauty and proximity to nature, to project these traits through the national animal. This raises the obvious question, how to other countries of the world decide their national animal? On what basis is the selection done?

1. Is the national animal selected to display a particular message about the country? (strength, beauty, courage)
2. Is it decided based on the major religion of the country?
3. Is the animal selected just because it is native to that country?

Or are there some other reasons as well?

Symbols have been used by humans for centuries. They are a great way to bring a sense of oneness in the soldiers of an army or people of a nation. Animals and birds have been a part of the symbols for nearly as long as the symbols have existed. For example, the ancient Roman army had a symbol for each legion. These symbols depicted animals like eagles, wolves or bears, to depict traits like strength, speed, ferociousness etc. This trend eventually translated into the modern world as choosing the national animal.

Ironically, the first animal to be selected as the national animal of a country was not even a real animal. It was a unicorn, which was selected as the national animal of Scotland. However, this trend would have to wait for three centuries before taking off. As countries began to gain independence from colonial Britain, among the first things they did was to gain a sense of identity by adopting national flags and animals.

For example, the United States of America became independent in 1776, in 1777 they adopted a national flag, and by 1782 had adopted the bald eagle as their national animal. The bald eagle, which symbolizes freedom, the idea upon which the country’s foundation was laid. One common pattern that is seen in all the countries is that the national animal is either exclusively or majorly found in that particular country, with exceptions being countries that have fictional or extinct animals, like unicorn or dodo. This, of course does not come as a surprise.

Nepal, a country in South Asia, has the cow as its national animal, as it is considered sacred in Hinduism, the major religion of that country. Many countries adopt national animals mainly to raise awareness about their conservation and to promote tourism. For example, the Ganga river dolphin is adopted as the national fish of India, in an attempt to raise awareness about their declining population due to the pollution of the river. Similarly, China has the Giant Panda as its national animal as a conservation attempt.

I analyzed the data for national animals of different countries by using data analysis tools, and then plotted the top ten choices for national animal. The subspecies have been clubbed together under the species name, for example the Asian elephant and the African elephant have been clubbed under the common species — elephant. The results were pretty interesting.

This graph shows that many countries of the world have preferred to choose national animals like lion (21 countries) and eagle (19 countries), which represent courage and strength, characters that were instrumental in the bloody history of mankind. Of the top ten, only parrots are the animals that are not perceived as strong and/or ferocious, which again clearly shows that the main purpose of national animals is to project power and inject hope in the minds of the common man.

The dataset used for this analysis can be downloaded from:

https://www.kaggle.com/datasets/rambomind/countries-and-their-national-animals

Thank you for reading!