There are millions of species in the world, but many are long extinct and their ancient fossils are all that remain behind. These traces of life have provided clues into the behavior and habitat of ancient people and their burial rituals, as well as extinct animal species, and why some remains have been found grouped together.

Ancient pet cemeteries have been located in Egypt, Sudan, and Siberia, suggesting that even thousands of years ago humans had a complex relationship with household animals, and some viewed these animals as beloved companions, taking time to bury them carefully. Other sites, like underwater caves, have uncovered pristine material relating to giant lemurs that once roamed Madagascar, and bat graveyards from the Dominican Republic.

Some of these fossils are on display at national parks and museums, others are protected excavation sites, and some have turned into popular dive locations frequented by tourists to the region. But one thing that all of these places have in common is that they are of tremendous historical importance, and are fascinating to learn about and see.

Below are 25 places where the ancient remains of animals and humans, as well as prehistoric creatures, have been located, offering the modern man a glimpse into the past.

25 A Mummified Dog Tomb in Egypt Found 8 Million Specimens

We have learned much about Ancient Egypt thanks to the artifacts that have been left behind, but one of the most interesting finds is a pet graveyard, which dates back more than 2,000 years. According to the Smithsonian, the Ancient Egyptians owned a wide range of pets, from the standard household pets we know today, like dogs and cats, to the more exotic creatures like hippos. And although mummified remains and fossils have been found many times, it is the findings of one catacomb at the Temple of Anubis in Saqqara that really stands out.

Within this catacomb, the remains of more than eight million animal mummies have been found, most of which were reportedly dogs.

24 A Whale Graveyard Was Found In A Desert (Of All Places) In Chile

There is a whale graveyard located in the middle of a desert in Chile. According to Hakai Magazine, when workers were widening the Pan-American highway they stumbled upon a remarkable find; fossilized whale bones of a number of species that had died millions of years ago.

The Atacama Desert attracted researchers who believe that the fossils located here were a result of a catastrophic event, and four separate strandings, which according to The Guardian, is believed to have happened over a period of 10,000 years.

23 Lake Natron Is A Beautiful Lake That Proves Deadly To Animals

Lake Natron in Tanzania is one of the most interesting destinations, but it’s also one where only a few species are able to survive because the alkaline waters (reaching a pH of 9 to 10.5, Unusual Places reports) seem to turn animals into stone. Well, not exactly, rather it’s a process of calcification by the sodium bicarbonate of the waters.

The remains are often quite detailed, and this creates a rather eerie atmosphere, which has become the focus of a set of pictures published in a book by photographer Nick Brandt.

22 The Purposeful Burial Of Dogs Offer A Glimpse Into Their Relationship With Humans 2000 Years Ago

Near the Arctic Circle in Siberia, archaeologists uncovered a dog graveyard, containing the 2,000-year-old fossils of five dogs, which according to LiveScience, were carefully buried. Archaeologists believe that dogs were working animals in the ancient Arctic village, but also pets.

The purposeful burial of the dogs seems to suggest that dog (or at least these specific dogs) has been man’s best friend for thousands of years, and the people in the area cared for their canine companions.

21 Canada's Badlands Are Home To A Great Many Dinosaur Fossils

According to The Guardian, the first dinosaur fossil was found in Canada in 1884, by a young geologist named Joseph Burr Tyrrell. It was located a few kilometers from the town of Drumheller, in Alberta.

The area has been a significant spot for archaeologists who have discovered fossils of these prehistoric creatures. And located in the heart of the Alberta badlands is the Dinosaur Provincial Park, which according to National Geographic is celebrated for its high quality and the sheer number of fossils.

20 Visitors To The Dinosaur National Monument Can See Fossils From The Mesozoic Era

There are many places across the globe that have found prehistoric fossils, but not all locations are equal. Take the United States’ Dinosaur National Monument, located on the southeast flank of the Uinta Mountains, as an example, because it is one of 30 National Park Service sites that allow visitors to gain access to fossils from the Mesozoic Era.

At the Dinosaur Quarry Exhibit Hall, visitors can view more than 1,500 bones which remain encased in rock -- a fascinating experience for any dinosaur lover.

19 The Discovery Of The Aztec Dogs Is Remarkable, Yet Mysterious

When excavating in the Aztec capital of Tenochtitlan in Mexico City, archaeologists made a remarkable discovery; a mass dog burial of 12 dogs.

According to National Geographic, these dogs were buried more than 5,00 years ago, but researchers are unclear on the reason as no particular pattern appears to have been followed with regards to their burial. What makes this particular dog burial significant, is that it was reportedly not associated with any human burial.

From this find, researchers hope to learn more about the role of dogs, and how they were viewed by the Aztecs.

18 Uncovering A Pterosaur Colony In Brazil Gave New Insight Into The Species

A new species of the flying dinosaur known as pterosaurs were found in the ancient Caiuá Desert in Southern Brazil. The researchers believed this species once lived around small lakes in the surrounding deserts, and the coast of northern Brazil, around 75 to 87 million years ago, Smithsonian reports.

But what made this discovery really special is that there were hundreds of fossils clumped together, making this a rare find. The fossils offer evidence to suggest that these particular pterosaurs specimens were sociable and lived in colonies.

17 Mammoths May Have Traveled To A Site For Salt, And This Became Their Graveyard

A graveyard of the prehistoric woolly mammoth was located in the Novodubrovsky village, Siberia, and according to The Mirror, it was one of the largest concentration of this animals bones that has ever been found.

It is believed the mammoths traveled to this location on at least two separate occasions to make use of the ancient 'salt lick' or 'mineral lick', Siberian Times reports. Some paleontologists believe that the woolly mammoth became extinct because of a lack of calcium, which triggered a bone disease.

16 Thousands Of Jurassic Turtle Fossils Were Located In China

In the northwest province of Xinjiang, China, the remains of more than 1,800 Jurassic turtles, dating back millions of years, were found. The theory as to why the mesa chelonia turtles were gathered here, some stacked on top of each other, is believed to be because of a severe drought.

According to CBS News, the turtles gathered in a remaining watering hole waiting for rain, but the hole dried up before the rain came, resulting in the mass graveyard. In fact, it is the rain that is believed to have washed the deceased turtles and river mud into one place, their final resting place.

15 A Special Spot In India Has Unique Fossils Of Marine Permian Rocks

The Marine Gondwana Fossil Park can be found in Manendragarh in the Surguja district, Chhattisgarh. The park can be visited all year round, except the rainy season, and according to the Indian government, it “is a unique exposure of fossiliferous marine Permian rocks.” What this means is it's a site where there is the presence of marine fossils, and it has been developed into a Geoheritage center.

According to Business Standard, the state government set up this center to offer protection to the rare flora and fauna in the area, but also to protect the fossils.

14 The Remains Of A 3,000-Year-Old Horse Were So Well Preserved It Suggests It Was A Prestigious Animal

The remains of a female chestnut-colored horse, referred to as the Tombos horse, was discovered more than five feet underground in a tomb in Sudan. According to Daily Mail, the animal was so well preserved that it still had hair on its leg, after 3,000 years. This careful and purposeful burial seems to suggest that the horse was a valued animal.

Professor Michele Buzo of the Purdue University explained that it was an intention burial, adding, “Remnants of fabric on the hooves indicate the presence of a burial shroud. Changes on the bones and iron pieces of a bridle suggest that the horse may have pulled a chariot.”

13 An Ancient Village Reveals Celts Created Monster Hybrids

Frankenstein is one of the most well-known tales of a monster, but it seems ancient man had started creating monsters long before Mary Shelley’s 1823 novel was published. Evidence of this was found in an Iron Age site near Winterborne Kingston in England, where archaeologists found hybrid animals (for example, a sheep with an extra head) buried as part of a Celtic ritual, Daily Mail reports.

It is believed that the inhabitants of this ancient village, dating back more than 2,000 years, buried these animal parts in storage pits beneath their home. The purpose, according to the publication, was ritualistic.

12 Mummified Penguins From Two Mass Events Were Found In Antartica

There have been many strange discoveries in the world, offering a glimpse into the past, and among these discoveries is the mass graveyard of the Adélie penguins. According to IFLScience, the Long Peninsula in eastern Antarctica is home to thousands of these mummified penguins, buried beneath layers of sediment.

The reason they came to be here is thought to be because of two mass events (dating back 750 years and then again 200 years ago) caused by adverse weather conditions related to climate change.

11 There Are Few Finds As Rare And Interesting As This Mid-Combat Fossil

It’s rare to find a fossil of an animal in mid-action, but this happened 74 million-year-old ago; in 1971, the fossils of a carnivorous velociraptor battling a plant-eating protoceratops were found in the Gobi desert in Mongolia.

The velociraptor was hunting its prey, but the protoceratops is believed to have put up a fight and its jaws locked around the arm of the predator. It is one of the most bizarre fossils because while the two creatures were in mid-combat, a sand dune is believed to have fallen on top of them, burying them in this position, New Scientist reports.

10 Europe's First Signs Of A Human Cemetery Were Discovered In Germany

Uncovering ancient remains of humans is not a one-off occurrence, but finding remains that have been buried in an unusual way is of interest.

Archeologists in Germany were surprised to make the discovery of multiple remains from individuals who lived during the Mesolithic era, with graves dating back 8,500 years. What makes this discovery unusual is two things; the first is the people of this time where hunters and gatherers, and according to National Geographic, anthropologist Bettina Jungklaus explained during this time it was unusual to “find multiple graves in one place.” This is also evidence of the first type of cemetery in Europe and Scandinavia.

The second reason this site is different is that there were the remains of a man who was entombed standing up.

9 The Waco Mammoth National Monument Offers A Glimpse Into The Lives Of These Ancient Beasts

The Waco Mammoth National Monument, is, as the name suggests, a national monument, spread across 100 acres of parkland along Texas’ Bosque River. What makes this particular location so special it because it has served as an excavation site for the now-extinct Columbian mammoths (Mammuthus columbi), and allows for a better understanding of this species behavior and habitat.

The first fossil was discovered in 1978, and now, visitors are able to view fossils of female mammoths, a bull mammoth, and even a camel.

8 Ancient Insect Fossils Tell The Story Of Their Diversity

There was a time when insect species were limited, but 237 million years ago there was, as Science Mag puts it, an “explosion of diversity.” This happened after a mass extinction event known as the Permian-Triassic around 252 million years ago.

The evidence of the change in insect life can be found in two massive fossil sites in China. The sites are reportedly ancient lake beds covered in layers of sandstone and rocks, and paleontologists found 800 fossils in these locations -- a rare and wonderful find as the publication notes fossils of insects are rare because they lack bones.

7 Giant Lemurs' Remains Have Been Located In Underwater Caves

We don’t typically think of lemurs as being gigantic primates, but there was a time when one species of lemur were so gigantic they were gorilla-sized. Madagascar was a very different place to what it is today, and many things were on a much bigger scale 5,000 years ago; evidence of this was found in three underwater caves on the island, located underneath the Tsimanampetsotsa National Park.

According to CNN, the caves held the bones of giant lemurs, in extremely good condition because they had been left untouched.

6 A Mass Cat Burial Suggests Owners Lovingly Laid Their Pets To Rest

During the Roman Era, in the port town of Berenike in Egypt, many people laid their domestic pets to rest. According to Ancient Origins, scientists have found the remains of 86 domestic cats, which are believed to have been buried carefully after dying from natural causes. Because of the way in which these animals were buried, makes this site different to others as it was not a place where spiritualistic rituals took place.

According to researchers, what this site shows is people lovingly putting their pet to rest, and should be thought of as a pet cemetery.