9 Animals You Never Knew Existed

The precise number of animal species that exists on Earth, both past and present, is unknown. Following this logic, there’s a plethora of animals they didn’t teach you about in school. Sure, lions, tigers, and bears (oh my!) are cool, but if you’re looking to expand your knowledge of the Animal Kingdom or just want to stock up on fun #animalfacts, check out these nine exceptional creatures.


Before you mistakenly categorize this primate as a chimp, take a closer look. The bonobo is one of the most rare and intelligent primates in the world; they’re only found in a small part of the Democratic Republic of Congo and, among other things, their social structure is unique, complex, and largely peaceful.


The agouti (ah GOO tee) is a rain forest-dwelling rodent from Central and South America. Given its diet of fallen fruit and nuts, it’s no secret that the agouti loves forest leftovers, but its sharp incisors also play a vital role in the survival of Brazil nut trees (one of the largest in the Amazon). This rodent species is the only mammal that can crack open the indestructible outer shell of a Brazil nut, which is extremely valuable for the country’s remote people.


Madagascar is home to some incredible species, and the fossa is the “king” of them. Even though resembling a morphed cat-like dog, a fossa’s closest relative is the mongoose, but the misunderstandings don’t end there. Legends of fossas stealing babies from cribs, licking humans into a deep trance, and making their own pupils disappear are endless, but let’s be honest, we prefer facts over a lengthy list of myths.


Imagine a buttery box of theater-style popcorn, and you can almost smell this next exceptional species. Yes, the smell that usually signifies box-office entertainment is the same smell you’ll find emanating from a binturong, aka bear cat. However, that moniker is a bit misleading since binturongs aren’t related to bears or cats but instead have closer ties to fossas mentioned above.


There are only two types of egg-laying mammals in the world, and the echidna is one of them. If that’s not enough to spark your interest, this spiny anteater is also one of Earth’s oldest surviving species. While other animals have been busy evolving and adapting to fluctuating environments, the echidna has remained unchanged since prehistoric times.


Speaking of anteaters, the tamandua (aka lesser anteater) is another mammal you probably didn’t know existed. Its relative, the giant anteater, gets most of the attention, but the tamandua has its own way of making its presence known; it can spray a rotten-smelling secretion that’s said to be significantly more powerful than a skunk. Thus, its unforgettable nickname, “stinker of the forest,” is properly attributed.

Tree pangolin

The tree pangolin is a scaly anteater that looks like a pinecone with legs and a long tail. Its scales are made of keratin, like our hair and fingernails, which protect this “pinecone” from predators.


Sure, the tuatara appears to be an average lizard, but this reptile is truly unique. The tuatara is specific to New Zealand and its closest relatives are an extinct group of reptiles that lived during the time of the dinosaurs. It’s no wonder the tuatara is referred to as a “living fossil.”


Caecilians (pronounced seh-SILL-yens) live a mysterious life in a network of underground tunnels. There are over 120 species of caecilians on at least 4 continents, but almost nothing is known of this amphibian’s habits or lifestyle.

Can you think of any uncommon animals to add to this list? Share yours in the comments below.

*Jenn Beening is the social media specialist for San Diego Zoo Global. Read her previous post, Ken and Dixie’s Bite Club.


Victor Lives On

Victor the echidna

At the end of April, the San Diego Zoo mourned the passing of probably its oldest mammal resident. He arrived here in 1956 and was believed to be more than 58 years old at the time of his death. Was he a great ape? An elephant? A rhinoceros? None of the above. Victor was a short-nosed echidna, a spiny, egg-laying mammal (called a monotreme) from Australia about the size of a large housecat. In his years in our Children’s Zoo, Victor touched (or at least was touched by!) thousands of visitors fascinated by this unusual and amazing creature. His death may have ended his long career as an animal ambassador, but even after death, Victor continues to be a source of important information and learning.

Part of our job in the Wildlife Disease Laboratories is to help ensure the health and well-being of the animals in our care. But no matter how well we do our job, all animals eventually reach the end of their natural lifespan, be it 6 years or 60. When this happens, we try to make the most of a difficult situation by turning it into an opportunity to share and to learn. What we learn from our animals after they die is very important and helps our living collection. We are keeping the live animals alive by learning from them after they pass away. Learning and sharing knowledge is a key role we play in the circle of life.

Thousands of Zoo visitors met Victor up close during his time with us.

When Victor died, his body came to us. We performed the animal version of an autopsy, called a necropsy, to look for disease and determine his cause of death. How do we do this? Well, if you’ve seen an episode of CSI or Bones, you probably have some idea, but the lesions of natural disease are different, and recognizing them depends first and foremost on knowing what is normal. As you can imagine, in our line of work, with the large diversity of animals we see, “normal” is relative! With their narrow, toothless beaks, lack of external ear flaps, internal testicles, and single opening for urogenital and digestive tracts (called a cloaca), normal for an echidna is certainly abnormal for most other mammals. In fact, it sounds more like a bird!

Never having seen the inside of an echidna, we relied on knowledge of the species, published information, and years of experience with other animals to separate abnormalities related to disease from normal anatomy. Luckily for us, there are generally more similarities than differences, and a disease in one species often looks the same in another. Ultimately, Victor’s problem, like many older primates and dogs, was his heart. A large, dilated heart with white streaks of scar tissue in its muscle points to heart disease in any animal. Victor had been undergoing treatment for heart failure when he died, and the necropsy findings confirmed the clinical diagnosis.

While this information about one animal might not seem like much, over time, with thorough documentation, knowledge of the common diseases in echidnas will help zoos screen their animals for these diseases and initiate treatment earlier. Tissues preserved from Victor on glass slides are now part of a museum-quality archive that can be used for future studies. Additional tissue samples went to other research divisions at the San Diego Zoo Institute for Conservation Research, where these precious specimens could provide important insights in the fields of genetics and reproductive physiology. His body was donated to a museum to be a source of learning and enjoyment for future generations.

Our collections are a finite and irreplaceable treasure of biodiversity, which is why we collect, conserve, and share biomaterials in support of nonprofit research that furthers our conservation and education mission. In this way, Victor lives on!

April Gorow is a research coordinator and Rachel Burns is the Steel Endowed Pathology Fellow, Wildlife Disease Laboratories, San Diego Zoo Institute for Conservation Research.