The Argentinosaurus is a genus of humongous sauropod dinosaurs that used to live during the Late Cretaceous period (66-100 million years ago) in present-day Argentina.
They are characterized by their gargantuan size, estimated to have hind legs as tall as 15 feet (4.5 meters), a trunk length of 23 feet (7 meters), and an overall body length of 98 feet (30 meters). Oh, and their estimated weight is around 60 to 100 tons.
In context, 98 feet, their length, is about half the height of the Leaning Tower of Pisa or two times as tall as the Hollywood sign. And the weight—ten to sixteen times more than your average elephant.

The Borealopelta, meaning northern shield in Latin, is a genus of ankylosaurs (herbivorous dinosaurs) from the Lower Cretaceous epoch (100–145 million years ago) that used to live in the area of present-day Alberta, Canada.
It was discovered at the Millennium Mine, an oil sands mine near Fort McMurray, Alberta, which is owned by the integrated energy company Suncor Energy.
This particular specimen is considered among the best-preserved dinosaur fossils of its size ever found. The fossil has managed to preserve numerous closely-spaced rows of small armor plates as well as its keratin sheaths, overlying skin, and the animal’s last meal found in its stomach.

Ammonites were marine mollusk animals that, according to researchers, went extinct during the famous Cretaceous–Paleogene (K–Pg) extinction event, or that time 66 million years ago when the comet hit the earth, making three quarters of the planet’s life extinct.
This particular one took a bit of a different route during its fossilization and began turning iridescent—developing bright and vibrant colors instead of the usual drab brown-grey affair. The one on the left was recovered in Madagascar, while the one on right, an even brighter specimen, was found in Alberta, Canada.

You know how many dinosaurs were absolutely enormous in size? Well, if you wanted to survive, you had to be big, just like this Stupendemys geographicus, a giant turtle that’s the size of your average sedan.
Measuring at 13 feet long and weighing in at 1.25 tons, this prehistoric beast had a shell that evolution designed for battle—one of their primary threats were Purussauri, a roughly 10-meter prehistoric species of caiman (a type of crocodile).
Some of the bits and pieces of fossils of the giant turtle had bite marks and punctured bones. One shell piece even had a tooth embedded in it—yep, of the same Purussaurus. So badass!

When you first look at it, you probably think “what the heck is that?” That, our kind readers, is the exceptionally well-preserved fossil of a dinosaur that not only has many of its bones intact, but also has detailed skin impressions.
Why is this important? Everything that humanity knew of dinosaur skin was based on small fragments that were found here and there, so finding a specimen that is as intact as this one equates to a paleontological sensation.
This particular dinosaur mummy was found and excavated back in 1908 by fossil collector Charles Sternberg and his sons. For a dinosaur that was naturally mummified between 66 and 68 million years ago, it is extraordinary to see its skin, hand, tendons, nostrils, stomach contents, and a number of other body parts mostly intact.

This one isn’t actually extinct as there are still a number of species of crinoids (more commonly called sea lilies, a kind of marine animal) still found in our oceans, but there are certainly creepy fossils of these specimens too.
The ones shown above are fossilized crinoids from the Carboniferous period (around 300-360 million years ago). Fun fact: it was the inspiration for the chestbursters and the full-grown xenomorph in the box office hit Alien.

It is lucky enough for archaeologists to find one fossil specimen, but finding hundreds in one place is the archaeological equivalent of hitting the jackpot.
Enter Whale Valley, or Wadi Al-Hitan, a paleontological site around 93 miles (150 kilometers) southwest of Cairo, Egypt that was designated a UNESCO World Heritage Site back in 2005 for its hundreds of fossils of some of the earliest forms of whale—the archaeoceti, a now extinct sub-order of whales.
Now, it is said that the fossils found at this side are not the oldest (from around 40–41 million years ago), but it is actually the great concentration of them in the area and their level of preservation that makes it mesmerizing. The site is especially valued for providing key insights into how whales evolved over the years.
Besides the ginormous whale fossils, there are also those of sharks, crocodiles, sawfish, turtles, and rays, which helped scientists reconstruct the surrounding environment and ecological conditions of the time.

The Altamura Man is the name of a fossil of a Neanderthal-era man from the Pleistocene Epoch that was discovered 27 years ago, back in 1993, among the stalagmites of a cave in Altamura, Italy.
Researchers say that the fossil is remarkably well-preserved for a batch of bones dating back 128,000 to 187,000 years. It was found embedded in stalagmites and covered in a thick layer of calcite, a mineral that preserved the bones, and was actually left untouched in the location to avoid damage to the fossil due to its precarious position.
Fun fact: the skeletal remains are found in a sinkhole leading to a 197-foot (60-meter) tunnel, which meant that conditions for preservation were perfect, but not so great for the Altamura man, who had fallen into this remote spot, was stuck, and quite likely had a slow death due to his sustained injuries, starvation, and lack of water.

Birth is a dangerous process as many things can go wrong, but for this Chaohusaurus, it all ended even worse. The 248-million-year-old fossil was found in South Majiashan, China back in 2011.
The mother was carrying at least three offspring: one was found under the mother’s body, the third was still inside her, waiting to be born, and the middle one, the second, was halfway out of the birth canal. A pretty unique sight to see in fossil form!
Unfortunately, only this particular portion of the mother was found because the team collected the rock back in 2011 and when they understood this, a year later, it was too late to recover the rest of the body. However, other specimens were retrieved to fill in the gaps about the species in general.

Given that malformation and genetic errors are quite a rarity as it is and given that fossils are a rarity in and of itself, the two can’t possibly be a thing at this point, right?
Wrong. Scientists have managed to find a fossil of an extremely rare reptile that would normally have one head, but instead has two. The Shenzhen Paleontological Museum has a specimen of this tiny long-necked reptile which it originally found fossilized in Yixian, Liaoning Province, northeastern China.
It is approximately 2.75 inches long (7 centimeters) and it is, in every aspect, similar to the other, non-malformed embryonic or possibly neonate skeletons that it has of these extinct reptiles, except this one has two equally proportional heads and necks, and it was confirmed that they actually belonged to the same individual and that it’s not some imprint of multiple bodies.
It is dated back to the Cretaceous Age—a time period that took place 65–145 million years ago. Different sources provide different specific dates, with most mainly focusing on a timespan of 120–125 million years ago.

It is unknown which particular dinosaur this tooth comes from, but over the many years, it managed to opalize in mesmerizing ways. But what is known is that it was found in Lightning Ridge, Australia.
Among the many different dinosaurs that are known to have lived in the area are the giant long-necked sauropods, 1.5-meter-long raptors called lightning beasts (Fulgurotherium), and the 6-meter carnivorous theropods Rapator ornitholestoides, among many others that used to live in the area, whether land, marine, or aerial.

It may sound like fossilization happens lightning fast—like taking a selfie—and makes everyone wonder, how could two prehistoric creatures get fossilized mid-battle? Well, it’s possible given a very small, but very crucial detail—the element of surprise on the part of nature.
In the picture, you can see a Velociraptor, a 6-foot (2-meter) tall, 180-pound (80-kilogram) dinosaur, and a Protoceratops, a 5.9-foot (1.8-meter) long herbivorous dinosaur, battling it out. Suddenly, a heavy sandstorm approaches and buries the two alive as they are too busy showing each other who’s boss.
And then, roughly 80 million years later, a group of Polish and Mongolian scientists found them in the southern part of the Gobi Desert, present day Southern Mongolia and Northern China.

A bit of an unusual entry in this list—and one that probably many of you didn’t really expect. This is the Lloyds Bank Coprolite, which is a fancy term for a fossilized turd. As the name suggests, it was found beneath the site of what was to become the York branch of Lloyds Bank back in 1972.
It measures in at 8 inches (20 centimeters) long and 2 inches (5 centimeters) wide, making it a bit bigger than a conventional flashlight. An analysis of the excrement showed that whoever produced it primarily ate meat and bread. It also included hundreds of parasitic eggs, suggesting that the human was suffering from intestinal worms.
Back in 1991, paleoscatologist Dr. Andrew Jones made international headlines with his comment on this finding, saying “This is the most exciting piece of excrement I've ever seen... In its own way, it's as irreplaceable as the Crown Jewels.”

One of the most recent additions—and most appropriate ones, it’s only one of the most famous dinosaurs in all of human history—was found in 2006, but only recently revealed to the public, a T-Rex with all of its bones completely intact. This Tyrannosaurus rex was found buried in sediment next to a Triceratops. Scientists believe that the two were engaged in a fight at the time of their demise. The fossil was hence nicknamed the Dueling Dinosaurs.
The fascinating specimen has 100% of its bones, all in their natural positions, which have held up quite well over the millions of years because of the sediment. Together with the Tricerotops, the fossils were described as some of the most important paleontological discoveries of our time.

Nicknamed after the state it was found in—in the Hell Creek Formation in North Dakota—this Edmontosaurus annectens fossil is about 67 million years old, dating back to the Maastrichtian age of the Cretaceous period. Researchers believe that it used to belong to a specimen that was about 35 feet (12 meters) long and weighed some 35 tons.
This particular skin fragment fossil is considered unusual and scientifically valuable—not only because bones are the much more typical find when it comes to fossils—but also because of the soft tissue of the specimen that includes skin and muscle. It gave a rare glimpse into the species and preliminary studies indicated that they had heavier tails and actually ran faster than was previously thought.

Would you have ever guessed that you’d one day witness a fossil of two turtles in the middle of their nature call during mating season?
Back in 1987, researchers stumbled upon an unusual 47-million-year-old fossil in the Messel Fossil Pit, Germany. Turns out, this pair of turtles were in the middle of their mating act in the middle of a lake when they sank a bit too deep—right where the toxic waters were—and died. It was toxic because it was a volcanic late, and the conditions were perfect for things to die and get fossilized there.
Turns out, humanity’s uncovered around 30 fossils of mating animals so far, so mating fossils aren’t such a rarity. But all of those were insects. This one, however, was the first ancient vertebrate, the Allaeochelys crassesculpta, to be fossilized mid-act.

Nova Scotia, Canada is home to a very unique geological formation called the Joggins Formation. It is the location of a number of fossils dating back to the Carboniferous period, which dates back to 298–358 million years ago.
Geologists consider this a significant location because of its saturation of fossilized plants and one of the best-preserved coal forests known to us. In particular, these trees are called lycopsids, roughly 98-foot (30-meter) tall trees with around 3.3-foot (1-meter) thick trunks. These trees are practically extinct, only existing in their distant relative form—as club moss.
What is most fascinating about them is that they have become fossils in an upright position. Some say this contradicts the conventional geological theories claiming that the layers in which things are fossilized were actually laid down over millions of years. However, this leads many to claim that these mostly-intact fossils of trees were buried very quickly, creating one huge layer.

Among the many different kinds of “-saurus,” there’s also a Brachylophosaurus, a mid-sized member of the hadrosaurid family of dinosaurs, most known for the flat duck-bill appearance of the bones in their snouts.
In July of 2000, a specimen of a Brachylophosaurus, which the world came to know as Leonardo, was unearthed. Much to everyone’s surprise, it had a fully articulated and even partially mummified skeleton and is now considered one of the most spectacular dinosaur finds ever.
Fun fact: despite there being no official record of this on the Guinness World Records website, according to the Children’s Museum of Indianapolis, it is said that Leonardo the Brachylophosaurus was even included in the Guinness Book of World Records as having the best-preserved dinosaur remains in the world.

Just like getting fossilized mid-battle, getting fossilized mid-meal is also something a quick burial has preserved well enough for researchers to find and study.
Sanajeh is a genus of a late Cretaceous madtsoiid snake from present-day western India. As you might have guessed, the species is extinct. Instead, here you see a 68-million-year-old fossil of said snake that was about to devour a titanosaur, but ended up being buried under a landslide along with all of the eggs in the dinosaur nest.
Not only is it a unique find, albeit not as well-preserved as some of the others in this list, but it’s also claimed to be the first evidence of snakes eating dinosaurs. These snakes didn’t have wide enough gapes to devour large animals, so they had to stick to smaller prey, and it turns out tiny dinosaur hatchlings were the right size.