15 of the Largest Animals in the World «TwistedSifter The blue whale (Balaenoptera musculus) is a marine mammal belonging to the suborder of baleen whales. At 30 metres (98 ft) in length and 180 metric tons (200 short tons) or more in weight, it is the largest known animal to have ever existed. The Blue Whale’s tongue weighs around 2.7 metric tons (5,952 pounds), about the size of an average Asian Elephant and its heart weighs about 600 kg (1,300 lb) and is the largest known in any animal. Not only is the heart similar size to a mini-cooper car but also comparable in weight. The Blue Whale is thought to feed almost exclusively on small, shrimp-like creatures called Krill. During the summer feeding season the Blue Whale gorges itself, consuming an astounding 3.6 metric tons (7,900 pounds) or more each day. This means it may eat up to 40 million krill a day with a daily calorie requirement of an adult Blue Whale in the region of 1.5 million.

[ Source ] The Heaviest Land Animal in the World: The African Bush Elephant The African Bush Elephant is the largest living terrestrial (land) animal, with males reaching 6 to 7.5 metres (19.7 to 24.6 ft) in length, 3.3 metres (10.8 ft) in height at the shoulder, and weighing 6 t (13,000 lb). Females are much smaller, reaching 5.4 to 6.9 metres (17.7 to 22.6 ft) in length, 2.7 metres (8.9 ft) in height at the shoulder, and weighing 3 t (6,600 lb). The adult African bush elephant generally has no natural predators due to its great size, but the calves (especially the newborn) are vulnerable to lion and crocodile attacks, and (rarely) to leopard and hyena attacks. [ Source ] The Tallest Land Animal in the World: The Giraffe Photograph by Luca Galuzzi – The giraffe (Giraffa camelopardalis) is an African even-toed ungulate mammal and the tallest living terrestrial animal in the world.

It stands 5–6 m (16–20 ft) tall and has an average weight of 1,600 kg (3,500 lb) for males and 830 kg (1,800 lb) for females. The giraffe has an extremely elongated neck, which can be over 2 m (6 ft 7 in) in length, accounting for nearly half of the animal’s vertical height. The long neck results from a disproportionate lengthening of the cervical vertebrae, not from the addition of more vertebrae. [ Source ] The Largest Carnivora in the World: The Southern Elephant Seal Photograph by DAVID SHACKELFORD The Southern elephant seal is the largest carnivore living today. This seals’ size shows extreme sexual dimorphism, possibly the largest of any mammal, with the males typically five to six times heavier than the females.

While the females average 400 to 900 kilograms (880 to 2,000 lb) and 2.6 to 3 meters (8.5 to 9.8 ft) long, the bulls average 2,200 to 4,000 kilograms (4,900 to 8,800 lb) and 4.5 to 5.8 meters (15 to 19 ft) long. The record-sized bull, shot in Possession Bay, South Georgia on February 28, 1913, measured 6.85 meters (22.5 ft) long and was estimated to weigh 5,000 kilograms (11,000 lb). Southern elephant seals dive repeatedly, each time for more than twenty minutes, to hunt their prey—squid and fish— at depths of 400 to 1,000 meters (1,300 to 3,300 ft). The documented diving records for the seals are nearly two hours for the duration, and more than 1,400 meters (4,600 ft) in depth.

[ Source ] The diverse order Carnivora includes over 280 species of placental mammals. Its members are formally referred to as carnivorans, while the word “carnivore” (often popularly applied to members of this group) can refer to any meat-eating organism. Carnivorans are the most diverse in size of any mammalian order, ranging from the least weasel (Mustela nivalis), at as little as 25 grams (0.88 oz) and 11 centimetres (4.3 in), to the polar bear and southern elephant seal. [ Source ] The Largest Reptile in the World: The Saltwater Crocodile The saltwater crocodile (Crocodylus porosus), is the largest of all living reptiles. It is found in suitable habitats from Northern Australia through Southeast Asia to the eastern coast of India. An adult male saltwater crocodile’s weight is 409 to 1,000 kilograms (900–2,200 lb) and length is normally 4.1 to 5.5 metres (13–18 ft).

However, mature males can exceed 6 metres (20 ft) and weigh more than 1,000 kilograms (2,200 lb) and this species is the only extant crocodilian to regularly reach or exceed 4.8 metres (16 ft). The saltwater crocodile is an opportunistic apex predator capable of taking nearly any animal that enters its territory, either in the water or on dry land. [ Source ] The Largest Bats in the World: The Giant golden-crowned flying fox Golden Crowned Flying Fox | Photograph by Latorilla Spectacled Flying Fox | Photograph by Mnolf The largest bat species is the Giant golden-crowned flying fox (Acerodon jubatus), an endangered fruit bat from the rainforests of the Philippines that is part of the megabat family. The maximum size is believed to approach 1.5 kg (3.3 lb), 55 cm (22 in) long, and the wingspan may be almost 1.8 m (5.9 ft). The Large Flying Fox (Pteropus vampyrus) is smaller in body mass and length, but it has been known to exceed the Golden-crowned species in wingspan.

Specimens have been verified to 1.83 m (6.0 ft) and possibly up to 2 m (6.6 ft) in wingspan. [ Source ] Photograph by Library of Congress Osteichthyes, also called bony fish, are a taxonomic group of fish that have bony, as opposed to cartilaginous, skeletons. The vast majority of fish are osteichthyes, which is an extremely diverse and abundant group consisting of over 29,000 species. It is the largest class of vertebrates in existence today. The largest living bony fish is the widely distributed ocean sunfish (Mola mola). It resembles a fish head with a tail, and its main body is flattened laterally.

The mature ocean sunfish has an average length of 1.8 m (5.9 ft), a fin-to-fin length of 2.5 m (8.2 ft) and an average weight of 1,000 kg (2,200 lb), although individuals up to 3.3 m (10.8 ft) in length 4.2 m (14 ft) across the fins and weighing up to 2,300 kg (5,100 lb) have been observed. [ Source ] The Heaviest Flying Bird in the World: The Dalmatian Pelican Photograph by Doug Janson The Dalmatian Pelican (Pelecanus crispus) is a member of the pelican family. It breeds from southeastern Europe to India and China in swamps and shallow lakes. This is the largest of the pelicans, averaging 160–180 cm (63-70 inches) in length, 11–15 kg (24-33 lbs) in weight and just over 3 m (10 ft) in wingspan.

With a mean weight of 11.5 kg (25 lb), it is the world’s heaviest flying bird species on average, although large male bustards and swans can exceed the pelican in maximum weight. [ Source ] Reptiles - Amphibians, Information on All Types of Lizards, Snakes, Frogs, Turtles, Amphibians, Scorpions, Tarantulas and Other Arthropods Reptiles Glossary of science terms used in the study and discussion of herptology and entomology, for reptiles, amphibians, and arthropods Reptiles - Amphibians Family Articles Enter your Freshwater Aquarium Enter parameters for your Freshwater Aquarium to get compatibility information while browsing. Enter your Saltwater Aquarium Enter parameters for your Saltwater Aquarium to get compatibility information while browsing. Fish Finder Search our database for compatible pets! Enter characteristics of what you are looking for and find them instantly. Dr. Jungle's Pets and Animal Speak - Newsletter Featured Pet of the week and more... Pet Talk People talking about their pets. Latest Fact Sheets New Arrivals and updates to Animal-World care sheets.

Animal Stories - See More We just got an ASN last Saturday and I'm trying to figure out what sex it is. I got an look at its tail last night and it looked like a female. Can anyone help me... (more) Katrine Smith I am equipped to breed 6 red eyed tree frogs; please reply Collette Pitt Looking for a way to buy bark scorpion in bulk, anyone out there have some for sell in a large quantity? Thanks. Chris I've been trying for so long to find an albino ball snake and I'm still researching for where to get them Isaiah Spider buyer's in Pakistan . . . We are the geniune buyers . . We purchase all kinds of spiders in Pakistan and outside Pakistan too . We are direct buyer there will be no mediator / broker in front , only direct buyer will be represent . . If you have any kind of spider kindly contact us , we challengue you nobody will offer much good rate then us . . Our minimum required weight is 50 gram and maximum more than 50 kg . . . Contact us directly at Hamzaali2166@gmail.com hamza ali I have full black scorpion in Afghanistan. If you are intrested to buy please let me know.

Gholam Hassan Ghola Hassan World of Reptiles, Amphibians, and Land Invertebrates Green snakes Opheodrys vernalis Herptiles and arthropods are ancient inhabitants of our planet, evolving as many as 350 millions years ago! The wondrous diversity of these many creatures has intrigued and fascinated people since the beginning of time. The reptiles, amphibians, and land invertebrates found in the animal world demonstrate an infinite variety of shapes, patterns, colors, and habitats. Learning about them is an exciting adventure. Our list of reptiles includes many types of lizards, snakes, different types of turtles, and tortoises. Amphibians include frogs, toads, salamanders and newts. Arthropods cover the arachnids, like spiders, tarantulas, scorpions and whip scorpions: myriapods containing centipedes and millipedes; and other land invertebrates. Each guide offers species information with their backgrounds, habitat, behaviors, and care. Pictures in each guide can help in choosing a pet or aid in identification. Reptiles - Amphibians - Species guides for Whip Scorpions.

Tailless Whip Scorpions (Whip Spiders), and Short-tailed Whip Scorpions with facts, pictures, pet care and handling. Reptiles - Amphibians Features Amphibians, Species List and Guides, Frogs, Toads, Salamander, Newt Centipede Care Centipede and Millipede Care, Keeping Myriapods as Pets Land Invertebrate Care Land Invertebrate Care, Keeping Arachnids and Other Arthropods as Pets Selecting Your Snake Pet Snakes, Choosing a Snake, Snake Care for All Types Selecting Your Lizard Pet Lizards, Choosing a Lizard, Lizard Care for all Types of Lizards Lizard Classifications Lizard Classification, Families of Lizards and Lizard Identification Rose Haired Tarantula Are Spiders Insects or Arachnids? This is the age-old question. Even if you donât particularly care for creepy crawlies, you most likely have, at one time or another, categorized spiders incorrectly. We are here to set the record straight. Biologists would turn ov. . . Guest Article Contributions Welcome!

Agalychnis callidryas (Red Eyed Tree Frog) Agalychnis callidryas (Red Eyed Tree Frog) Dr. Jungle's YouTube Channel - Reptiles About Reptiles, Amphibians and Arthropods Reptiles, amphibians and land invertebrates are extremely ancient creatures, and have been a part of many culture's folklore for many generations. A good example is the snake. Snakes gained an evil reputation in their depiction in the Garden of Eden, yet they have also become a symbol of health, hygiene, and medicine, as depicted by the snake entwined around the Greek god of healing, Aesculapius. In natural science, amphibians and reptiles are bundled together as the study of Herpetology, which is a branch of Zoology. Collectively they are known as herps, herptiles, or herpetofauna. The term “herpetology” is derived from the Greek word “herpton”, meaning a creeping thing. Herptiles are vertebrates and include both reptiles and amphibians.

The animal world is inhabited with approximately 58,000 species of vertebrates, which seems like a lot, yet is only about 3% of all animal species. Invertebrates make up the bulk of the animals at 97% of the species. The arthropods are land invertebrates and include the arachnids (scorpions, whip scorpions, and tarantulas), centipedes, millipedes, and many others. In more recent times, keeping these amazing animals as pets has seen an explosion of interest. The number of both professional and amateur herpetologists is greatly increasing. This has been helped by improvements in communications and the growing interest in wildlife, impassioned by ever improving nature films and documentaries. This interest has continued to develop and grow the hobby, and has resulted in an increased knowledge of breeding techniques and general herptile care. The ultimate reward for both the animal world and humanity, is people equipped with knowledge and the ability to help maintain and possible save many endangered species from extinction. Keeping Reptiles, Amphibians and Arthropods as Pets Keeping reptiles, amphibians, and land invertebrates is a fascinating hobby, and has many advantages over other types of pets.

The terrarium requires very little space and can be an aesthetically pleasing showpiece. A terrarium with plants, mosses, driftwood, and rocks brings a touch of nature into a city centered home or apartment. These creatures are generally quiet, clean, odorless, and non-demanding. Once the terrarium is setup, the cleaning and maintenance chores are minimal. Most species do not need feeding everyday, which is a distinct advantage during holidays. Animal-World species guides are provided for reptiles and amphibians, collectively known as herptiles, and land invertebrates like spiders, tarantulas, scorpions and more, collectively known as antrhopods. These guides help with identification and the care of individual species. A beginner will learn about herptiles and arthropods, be able to set up a terrarium, and obtain healthy animals. They will learn to be able to keep them successfully, and may even breed them. Each guide has in-depth species information covering everything from their native place of origin and when first scientifically described, the habitats and behaviors of each species, and the care needed to keep them as a pet.

Pictures for each type of reptile, amphibian, or land invertebrate are provided within each guide. These not only help with species identification, but aid in choosing the right pet. Reptile Facts Reptiles are a group of vertebrates with over 8225 species and are found in all regions of the world except for Antarctica. They are characterized as ectothermic (cold-blooded) vertebrates that breathe, and their skin is covered with scales and/or scutes. Most reptiles are oviparous (egg-laying) animals with the exception of some ovoviviparous (live-bearing) constrictor snakes and vipers. An ovoviviparous reptile holds the eggs inside its body until they hatch and then the living young are delivered. Reptiles are members of the Reptilia class, which include four living orders as well as fossil groups like the dinosaurs. Squamata The order Testudines includes the turtles, terrapins and tortoises with about 300 species Crocodilia The crocodilians in the order Crocodilia include the crocodiles, gavials, caimans, and alligators.

There are 23 species Sphenodontia The tuataras from New Zealand are in the order Sphenodontia with just 2 species. The Reptilia class also includes fossil groups like the dinosaurs. It is estimated to have been during the Carboniferous period, about 320-310 million years ago, that the first reptiles evolved from advanced reptile-like amphibians. Amphibian Facts Amphibians are characterized as ectothermic (cold-blooded) tetropods (vertebrate animals that have four limbs) with non-terrestrially adapted eggs. Most have a life cycle moving from a water-breathing juvenile form with gills, to an adult air-breathing form. There are some, however, that retain the juvenile gills into adulthood, and remain in this state for their entire lives. Amphibians are a relatively small group of vertebrates with over 6500 species. They belong in the class Amphibia which includes three orders. Anura Newts and salamanders are of the order Caudata.

Gymnophiona The lesser-known limbless caecilians of the order Gymnophiona superficially resemble earthworms or snakes and mostly live hidden in the ground. Frogs, toads and salamanders have been creeping along on the earth for millions of years before humans evolved. It is estimated to be about 350 million years ago that the first fishes came out of the water onto the land and evolved into the first amphibians. Arthropod Facts The land invertebrates included here are all arthropods, and members of the Phylum Arthropoda. Arthropods are invertebrate animals. They have an exoskeleton (external skeleton), a segmented body, and jointed appendages. Within the Arthropoda Phylum, they are classed as follows: Arachnids The Arachnids include the tarantulas, scorpions and the whip scorpions, more commonly called vinegaroons or vinegarroons. They are all members of the Arachnida class of joint-legged invertebrate animals in the subphylum Chelicerata. All arachnids have eight legs, and almost all are terrestrial. A few, however, inhabit freshwater and marine environments as well.

Arachnids comprise over 100,000 named species including spiders, scorpions, harvestmen, ticks, mites and Solitude. Tarantulas Tarantulas are spiders in the order Araneae. They are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids Anatomically, spiders differ from other arthropods in that the usual body segments are fused into two tagmata, the cephalothorax and abdomen, and joined by a small, cylindrical pedicel. Unlike insects, spiders do not have antennae. Scorpions Scorpions belong in the the order Scorpiones. These arthropods have eight legs and are distinguished by the pair of grasping claws and a thin segmented tail. The tail arches forward over the back with a venomous stinger on the end. They range in size from and incredibly small .35 of an inch (8.5 mm) up to 8.33 inches (21 cm). Scorpions are predatory animals found on all continents except Antarctica. There are about 1,752 described species.

Whip Scorpions Whip Scorpions These are arachnids in the order Thelyphonida, and are commonly referred to vinegaroons, or vinegarroons. The name whip scorpions came about because most of them resemble true scorpions due to their whip-like tails. Thelyphonids were previously in the Uropygi order, so in the scientific community they are also often called Uropygids. Whip Scorpions range mostly between 1 to 3 1/3 inches (25 - 85 mm) in length and are not as big as the largest of the scorpions. Short-tailed Whip Scorpions These are smaller soft-bodied arachnids in the order Schizomida. Schizomids superficially resemble spiders. They are also similar to Whip Scorpions in appearance but are much smaller, generally less than 1/5th of an inch (5 mm) in length. Tailless Whip Scorpions, Whip Spiders Tailless Whip Scorpions are arachnids in the order Amblypygi, and are often called Whip Spiders.

The term "amblypygid" means "blunt rump", which relates to their lack of a tail like that found on the Whip Scorpions, or Thelyphonids. The body of the Amblypygid's are broad and flat, with a solid carapace and a segmented abdomen. They have large, rather pincher-like pedipalps for grabbing prey. Despite their appearance, Tailless Whip Scorpions are totally harmless to humans. Myriapods The Myriapods are "many legged" arthropods containing nearly 13,000 species. They have bodies that are elongated and segmented. Each segment has a pair of legs, or appendages, and like insects their appendages have only one branch, or ramus. The number of appendages can vary from fewer than ten to nearly 200 pairs of legs. Myriapods are terrestrial, and most live in humid environments. They are found in soils, leaf litter, or under stones and wood. Most species have specialized glands, repugnatorial glands, that secrete a foul-tasting substance, and function as a defense.

Centipedes The Centipedes are members of the Chilopoda class of invertebrates in the subphylum Myriapoda. They are elongated metameric invertebrates with one pair of legs per body segment. The number of legs varying by species, from under 20 to over 300. There are estimated to be about 8,000 species of centipedes. Centipedes are carnivores and are unique in that they have "forcipules", a pair of venom claws formed from a modified first appendage. Some centipede species can be hazardous to humans because of their bite, Although the bite is painful, it is unlikely to be fatal to an adult. But it can be dangerous to children or those allergic to bee stings, and could induce anaphylactic shock in such people. Millipedes The Millipedes are members of the Diplopoda class of invertebrates in the subphylum Myriapoda. this class contains about 10,000 species. Most millipedes have very elongated cylindrical bodies, segmented with two pairs of legs per segment.

However they have no legs on the first segment behind the head, and then only one pair of legs on the next few segments, but two pairs of legs per segment after that. These are mostly slow moving detritivores, that feed on decaying leaves and other dead plant matter. Other Arthropods Other land invertebrates like the Hissing Cockroach, are members of the Insecta class, and are within the Phylum Arthropoda How Titanoboa, the 40-Foot-Long Snake, Was Found | Science | Smithsonian Contact Privacy Policy Terms of Use How Titanoboa, the 40-Foot-Long Snake, Was Found In Colombia, the fossil of a gargantuan snake has stunned scientists, forcing them to rethink the nature of prehistoric life Titanoboa, pictured with a dyrosaur and a turtle, ruled the swampy South American tropics 58 million years ago.

(Jason Bourque / University Of Florida) By Guy Gugliotta Smithsonian Magazine | Subscribe April 2012 In the lowland tropics of northern Colombia, 60 miles from the Caribbean coast, Cerrejón is an empty, forbidding, seemingly endless horizon of dusty outback, stripped of vegetation and crisscrossed with dirt roads that lead to enormous pits 15 miles in circumference. It is one of the world’s largest coal operations, covering an area larger than Washington, D.C. and employing some 10,000 workers. The multinational corporation that runs the mine, Carbones del Cerrejón Limited, extracted 31.5 million tons of coal last year alone. From This Story [×] CLOSE As a part of their documentary, the Smithsonian Channel asked sculptor Kevin Hockley to create a full-size replica of Titanoboa. (Robert Clark/Institute) Titanoboa, pictured with a dyrosaur and a turtle, ruled the swampy South American tropics 58 million years ago. (Jason Bourque / University Of Florida) Paleontologist Carlos Jaramillo at the Cerrejón coal mine.

(Joana Toro / Getty Images) (Guilbert Gates) In Gainesville, Jonathan Bloch (left) and Jason Head sort through thousands of fossils from the giant Colombian coal mine. (Brian Tietz) A Titanoboa vertebra dwarfs that of a modern 17-foot anaconda. (Brian Tietz) The model will be on display at a new exhibit at the National Museum of Natural History in Washington, D.C. (Robert Clark/Institute) Kevin Hockley and his model of Titanoboa. (Courtesy of Robert Clark / INSTITUTE) (Paul Mirocha) From the Castle: Big Snakes Cerrejón also happens to be one of the world’s richest, most important fossil deposits, providing scientists with a unique snapshot of the geological moment when the dinosaurs had just disappeared and a new environment was emerging. “Cerrejón is the best, and probably the only, window on a complete ancient tropical ecosystem anywhere in the world,” said Carlos Jaramillo, a paleontologist at the Smithsonian Tropical Research Institute. “The plants, the animals, everything.

We have it all, and you can’t find it anywhere else in the tropics.” Fifty-eight million years ago, a few million years after the fall of the dinosaurs, Cerrejón was an immense, swampy jungle where everything was hotter, wetter and bigger than it is today. The trees had wider leaves, indicating greater precipitation—more than 150 inches of rain per year, compared with 80 inches for the Amazon now. Mean temperatures may have hovered in the mid- to high-80s Fahrenheit or higher. Deep water from north-flowing rivers swirled around stands of palm trees, hardwoods, occasional hummocks of earth and decaying vegetation. Mud from the flood plain periodically coated, covered and compressed the dead leaves, branches and animal carcasses in steaming layers of decomposing muck dozens of feet thick. The river basin held turtles with shells twice the size of manhole covers and crocodile kin—at least three different species—more than a dozen feet long. And there were seven-foot-long lungfish, two to three times the size of their modern Amazon cousins. The lord of this jungle was a truly spectacular creature—a snake more than 40 feet long and weighing more than a ton.

This giant serpent looked something like a modern-day boa constrictor, but behaved more like today’s water-dwelling anaconda. It was a swamp denizen and a fearsome predator, able to eat any animal that caught its eye. The thickest part of its body would be nearly as high as a man’s waist. Scientists call it Titanoboa cerrejonensis. It was the largest snake ever, and if its astounding size alone wasn’t enough to dazzle the most sunburned fossil hunter, the fact of its existence may have implications for understanding the history of life on earth and possibly even for anticipating the future. Titanoboa is now the star of “Titanoboa: Monster Snake,” premiering April 1 on the Smithsonian Channel. Research on the snake and its environment continues, and I caught up with the Titanoboa team during the 2011 field season. Jonathan Bloch, a University of Florida paleontologist, and Jason Head, a paleontologist at the University of Nebraska, were crouched beneath a relentless tropical sun examining a set of Titanoboa remains with a Smithsonian Institution intern named Jorge Moreno-Bernal, who had discovered the fossil a few weeks earlier.

All three were slathered with sunblock and carried heavy water bottles. They wore long-sleeved shirts and tramped around in heavy hiking boots on the shadeless moonscape whose ground cover was shaved away years ago by machinery. “It’s probably an animal in the 30- to 35-foot range,” Bloch said of the new find, but size was not what he was thinking about. What had Bloch’s stomach aflutter on this brilliant Caribbean forenoon was lying in the shale five feet away. “You just never find a snake skull, and we have one,” Bloch said. Snake skulls are made of several delicate bones that are not very well fused together. “When the animal dies, the skull falls apart,” Bloch explained. “The bones get lost.” The snake skull embraced by the Cerrejón shale mudstone was a piece of Titanoboa that Bloch, Head and their colleagues had been hoping to find for years. “It offers a whole new set of characteristics,” Bloch said. The skull will enhance researchers’ ability to compare Titanoboa to other snakes and figure out where it sits on the evolutionary tree. It will provide further information about its size and what it ate.

Even better, added Head, gesturing at the skeleton lying at his feet, “our hypothesis is that the skull matches the skeleton. We think it’s one animal.” Looking around the colossal mine, evidence of an ancient wilderness can be seen everywhere. Every time another feet-thick vein of coal is trucked away, an underlayer of mudstone is left behind, rich in the fossils of exotic leaves and plants and in the bones of fabulous creatures. “When I find something good, it’s a biological reaction,” said Bloch. “It starts in my stomach.” Cerrejón has provided Bloch with many such moments. The search for the river monsters of the Paleocene Epoch began here by accident 18 years ago, when Colombian geologist Henry Garcia found an unfamiliar fossil. He put the specimen in a coal company display case, where it was labeled “Petrified Branch” and forgotten. Nine years later, Fabiany Herrera, an undergraduate geology student at Colombia’s Industrial University of Santander, in Bucaramanga, visited Cerrejón on a field trip. Tramping around the coal fields at the mining complex, he picked up a piece of sandstone and turned it over. There was an impression of a fossil leaf on it.

He picked up another rock. Same thing. And again. Herrera showed his discoveries to Jaramillo, who was working for the state oil company at that time and suspected that Cerrejón might have a lot more to offer than interesting rocks and coal formations. He and Herrera organized a full-scale expedition to Cerrejón in 2003 and invited paleobiologist Scott Wing, curator of fossil plants at Smithsonian’s National Museum of Natural History, to join them. Most fossils, plant or animal, are found either in temperate climates or in isolated niches in the tropics, such as deserts or high altitudes, where wind blows away sand and stone to expose ancient remains. Other fossils near the Equator lie buried and inaccessible beneath millions of tons of soil and vegetation. At Cerrejón, the quest for coal had stripped away this shroud. Herrera, with help from other researchers, spent four months at Cerrejón, collecting more than 2,000 plant specimens from several different pit mines. He did not know what to expect, because no one had ever explored a site of Cerrejón’s age and location.

Instead of an ancient forest filled with unfamiliar species, “the plants were all relatives of stuff we find today,” Herrera said. “We’ve got chocolate, coconuts and bananas and legumes—not as diverse as today, but the origins of the modern South American rainforest are suddenly there.” When Wing arrived at the mine, he looked in the coal company display case and decided that the “Petrified Branch” was not what it seemed—and that plants were not the only attraction in Cerrejón. “I had a point-and-shoot camera,” Wing recalled. “Early in the visit I asked if the company could open the cabinet, but nobody could find the key.” Wing took some pictures through the glass, returned to the United States and e-mailed them to Bloch at the University of Florida in Gainesville, a collaborator on an unrelated project. “I flipped out,” Bloch said. He was looking at part of the fossil jawbone of a land animal. Terrestrial vertebrates of that age had never been seen in the tropical latitudes of South America. The jawbone came from a dyrosaur, a very large crocodile-like creature now extinct. The fossil signaled that there were probably other vertebrate discoveries to be made.

Bloch and Wing immediately made plans for another trip and met Herrera and Jaramillo in Cerrejón. Wing showed Bloch the display case and started wiggling the lock. The glass broke. Wing reached in, plucked out the dyrosaur specimen and found a second bone hidden behind it, which “looked like a piece of pelvis,” Wing recalled. It was. Garcia explained he had found the fossil at a mine site known as the Expanded West Pit. He took the visitors there. A layer of coal had been removed from the surface, leaving a vast expanse of naked mudstone baking in the tropical sun. “It was covered with turtle shells,” Herrera recalled. They were bleached white and shimmering in the heat. The team collected fossils and returned to Gainesville. Over the next few months, U.S. and Colombian students explored other Cerrejón sites and e-mailed photos to Bloch. The La Puente Cut, an enormous open pit covering 6,000 acres of Cerrejón’s North Zone, appeared to be the most promising. “I was extremely excited,” Bloch recalled.

“I was sure we were going to see unbelievable stuff down there.” La Puente is a forbidding, naked surface of soft mudstone cut by gullies leading downslope to a lake filled with runoff and groundwater. The only vegetation is an occasional scraggly bush clinging to the scree. The pit shimmers at temperatures above 90 degrees Fahrenheit, while a hot wind blows constantly, with 25-mile-per-hour gusts. Methane fires belch periodically from the naked cliff face across the lake. Immense trucks can be spotted in the distance, driving loads of coal scooped up after blasting. The mudstone was the paleontological pay dirt. “Wherever you walked, you could find bone,” Bloch said, recalling the wonder of the first trip. During that expedition, in 2004, the researchers grabbed everything they saw, and everything was big: ribs, vertebrae, parts of a pelvis, a shoulder blade, turtle shells more than five feet across. They found bits of dyrosaur and turtle everywhere, and other animals as well, but the team could not sort everything immediately. They put what they could in plastic bags, then dug pits and cast the big pieces in plaster of Paris.

“It’s like prospecting,” Bloch said. Walk along with brushes and tweezers and eyes focused on the ground until you find something you want. Put the little bits in plastic bags and label them. Mark the bigger pieces on a GPS device and come back the next day with plaster and a tarp. Wait too long, and the GPS reading is useless: The rain is a curse, washing everything down the slope, never to be seen again. But the rain is also a blessing, for when it stops, a whole new fossil field lies open for exploration. For the next five years, Bloch and Jaramillo led field trips to Cerrejón and sent a steady stream of vertebrate fossils to Gainesville. Many of the remains looked a bit like those from modern animals, only much bigger. One new species of turtle was five and a half feet long, 67 percent larger than today’s biggest Amazon river turtles. Although there are no modern dyrosaurs to compare with the fossils, University of Florida graduate student Alex Hastings described three new species, one of which was between 15 and 22 feet long.

Another beast was a “dietary generalist,” Hastings said, who “could eat the large turtles.” It had huge jaws and a “death bite” that could penetrate the shell 1.5 feet in from its edge. “These are big animals.” In 2007, Hastings was inspecting a shipment of fossils labeled “crocodile” and noticed a strange—and very large—vertebra. To his trained eye, it was clearly “not from a croc.” He showed it to fellow graduate student Jason Bourque, a fossil conservationist and reptile specialist. “That’s a snake,” Bourque said. He delved into the university’s reptile collections and came up with the vertebra of an anaconda. It was smaller but reasonably close in appearance to the fossil. Bloch, Hastings and the rest of the team began ransacking the Cerrejón specimens. Fresh expeditions visited La Puente to search for more pieces of fossil snake. Eventually the team collected 100 snake vertebrae from 28 different animals. “We’d had some of them for years,” Bloch said. “My only excuse for not recognizing them is that I’ve picked up snake vertebrae before.

And I said, ‘These can’t be snake vertebrae.’ It’s like somebody handed me a mouse skull the size of a rhinoceros and told me ‘That’s a mouse.’ It’s just not possible.” Except, apparently, it was. “I needed to know how big the snake was, so I called the only guy in the world who would be able to tell me,” Bloch said. That was Jason Head, then working at the University of Toronto. They had met in the early 1990s when Bloch was a graduate student at the University of Michigan and Head was an undergraduate. Bloch gathered up “a whole bunch” of bone samples, carried them into his office and called up Head for a computer iChat. He held up a vertebra so Head could see it. Was this a snake? “I’m buying my ticket tonight,” Head said. Head spent several days in Gainesville with the Cerrejón researchers. They focused on the vertebrae from two different fossil snakes. Head noticed immediately that the creature had a T-shaped spine and that the bones had a number of characteristics that were unique to “boid” snakes—the lineage that includes boa constrictors and anacondas.

Both species are common in South America today. Boas can be up to 14 feet long and weigh as much as 100 pounds. Anacondas can exceed 20 feet and weigh more than 500 pounds. The bones of the Cerrejón snake suggested it was closely related to boas, but the Cerrejón environment offered a lifestyle more like that of the modern South American anaconda, a water dweller comfortable in both swift-moving rivers and swamps. And even though anacondas are big, these snakes were much bigger. How big? The problem with sizing ancient snakes is that you never have the whole spine in a neatly articulated row. You get individual bones, maybe pairs and occasionally three together. And unless you can place individual vertebrae in their correct position along the spine, you cannot know the animal’s length. Head and Indiana University paleontologist P. David Polly for two years had been building a mathematical model of a snake spinal column based on living species.

Snake vertebrae, as Polly explained, are “lovely and complicated, and there are some characteristics that are common to all snakes.” By examining these joints, ridges and knobs, and describing individual vertebrae as sets of coordinate points on a graph, Head and Polly created a template for all snakes. Over the course of evolution “snakes get bigger by adding more vertebrae,” Head said, and there can be as many as 300 vertebrae in the spinal column of a modern python, boa or anaconda. “But the big ones get more vertebrae only up to a point, then the vertebrae just get bigger.” After developing coordinates for individual Titanoboa vertebrae, Head and Polly used the model to position them in their correct spinal location and determine Titanoboa’s length.The team published its first results in Nature in early 2009, saying Titanoboa was between 42 feet and 49 feet long, with a mean weight of 2,500 pounds. The Cerrejón vertebrae were all of comparable size even though they were from different animals. With Titanoboa, enormous was the rule, not the exception.

The Cerrejón team had found what appeared to be an authentic primeval monster. Titanoboa was as long as a school bus and weighed as much as a small rhino. Aside from the boid-style vertebrae, however, that was about all that could be said about the creature at first. The discovery last year of the Titanoboa skull was key to advancing the research. “It’s not beautiful, but it’s a snake skull and there aren’t many of those,” Bloch said. “When we went down to Cerrejón, we thought ‘Well, pie in the sky we’ll find a skull of Titanoboa—’” “—and then we did,” Head added. They were sitting side by side in Bloch’s Gainesville office, in front of two microscopes. The process of assessing new bones from a fossil like Titanoboa is tedious and repetitive. They were comparing the contours of individual skull bones with exquisitely preserved modern boa, anaconda and python skulls from the university’s snake collections. Bloch and Head wanted to determine if their first analysis—that Titanoboa was more boa than anaconda—would hold up.

Fragments of jawbone suggested that Titanoboa’s mouth and whole head could have been over two feet long. A quadrate—a hinge bone connecting the lower jaw to the skull—enabled the back of the lower jaw to extend behind Titanoboa’s brain. Its mouth could “open big and open wide,” Head said. There was at least one inconsistency, however. By looking at the number of holes in the jawbone fragments, Bloch and Head concluded that Titanoboa had more closely packed teeth than modern-day boas. “Is it more a specialized fish-eater?” Head asked. “If you’ve got lots of teeth, it’s easier to grab slippery, scaly fish.” As far as Titanoboa was concerned, however, it probably did not matter. The crocs and the turtles undoubtedly ate fish, but Titanoboa was at the top of the food chain. It could eat fish, but it could also eat the crocs and turtles. “Some snakes—especially anacondas—can and do eat crocodilians,” Head said. “Still, wouldn’t it be strange if, instead of a monster, this is just a big, lazy snake that sits on the bottom grabbing fish as they swim by?” Bloch laughed.

“I don’t think so.” Eventually they agreed that Titanoboa’s skull was different from that of other boas, but they couldn’t determine if the extinct animal was more closely related to a boa or anaconda. The size of the snake immediately raised questions about how it got to be that big, and what it needed to survive. The Cerrejón team concluded in 2009 that Titanoboa had to have lived in a climate with a mean ambient temperature between 86 and 93 degrees Fahrenheit, substantially higher than the hottest average for today’s tropical forests, which is 82 degrees. That assertion, Head acknowledged, “has been extremely controversial.” For the past several years, the Titanoboa researchers and other experts have been trying to understand and model the climate that the giant snake lived in. There’s been some disagreement about how best to estimate the temperature 58 million years ago. Titanoboa was a coldblooded animal whose body temperature depended on that of its habitat. Reptiles can grow bigger in warmer climates, where they can absorb enough energy to maintain a necessary metabolic rate. That’s why insects, reptiles and amphibians tend to be larger in the tropics than in the temperate zone.

In this view, extraordinary heat is what made the snake a titan. The same principle would explain why ancient turtles and lungfish of Cerrejón were, like Titanoboa, much larger than their modern relatives. The relationship between coldblooded body mass and ambient temperature was the subject of a 2005 study by researchers at the Nuclear Physics Institute in St. Petersburg, Russia. By examining species sizes at a variety of different ambient temperatures, Anastassia Makarieva and colleagues calculated how fossils could be used to estimate temperatures in the distant past. Head and Bloch used the Russian data, plus information about today’s anacondas and their Amazon habitat, to conclude that Titanoboa would have needed surprisingly warm temperatures to survive in ancient Cerrejón. Several researchers, however, disagree with their conclusion. Paleoclimatologist Kale Sniderman, of the University of Melbourne in Australia, is skeptical of Makarieva’s approach. He noted that an ancient lizard from temperate Australia grew to at least 16.5 feet in length. Applying the model to that fossil predicts that lizards currently living in tropical areas should be capable of reaching 33 feet.

In another critique, Stanford’s Mark Denny, a specialist in biomechanics, says the Titanoboa researchers have it backward: The snake was so large and was producing so much metabolic heat that the ambient temperature must have been four to six degrees cooler than the team’s estimate, or the snake would have overheated. Head, Bloch, Polly and Jaramillo defended the team’s approach, but they acknowledge that their original estimate may have been a bit high. Recent data derived from nearby marine core samples have suggested temperatures closer to 82 to 88 degrees. Even so, they said, Titanoboa’s forest was much warmer than tropical forests today. Analyses of fossilized leaves from that forest support the idea that it was sweltering. Jaramillo and Herrera studied carbon isotopes in the leaves and the density of pores that let water in and out. They calculated that the levels of carbon dioxide in the atmosphere were 50 percent higher than today, which would have led to high temperatures on land. This fits with estimates from other techniques that the mean temperature was at least 82.5 degrees, and probably considerably higher.

The temperature has implications for how species survived in the tropics—and how they will survive as the climate changes. The rapid contamination of earth’s atmosphere by greenhouse gases like carbon dioxide is causing global warming, a phenomenon, which, if unchecked, may cause massive die-off in species that can’t cope with the heat. As temperatures rise, at some point plants should become unable to photosynthesize properly. “Figuring out when the different plant groups max out is a difficult question,” said Wing. “When a plant can’t shed the heat, it eventually dies.” During the time of Titanoboa, said Jaramillo, “we find a very productive forest, with a lot of biomass.” If Titanoboa and its lush ecosystem were in harmony at high temperatures, then global warming may not lead to ecological catastrophe—at least for some plants. “Perhaps modern plants have the ability to cope,” Jaramillo said. Jaramillo and other members of the Titanoboa team, however, point out that coping with climate change is a lot easier if you have millions of years to adapt to the warming trend.

Making the adjustment in 200 years, as cli­matologists characterize the pace of today’s greenhouse effect, or even 2,000 years, is a different matter altogether. The paleontologists will return to Cerrejón this year to look for more fossils, more species and more evidence of what the world was like near the Equator 58 million years ago. “The hardest thing to know about the past,” Wing said, “is how different it was.” Like this article?

Question: What type of animal is the world's largest reptile?
Answer: Crocodile