Brief Summary
This video explores 16 different members of the Dromaeosauridae family, commonly known as raptors. It covers their physical characteristics, habitats, hunting behaviors, and evolutionary relationships. The video highlights both well-known raptors like Velociraptor and Deinonychus, as well as lesser-known species, providing a comprehensive overview of this diverse group of dinosaurs.
- Raptors were bird-like meat-eating dinosaurs that thrived during the Cretaceous period.
- They were widespread, with fossils found on multiple continents.
- Raptors exhibited a range of sizes, from crow-sized to wolf-sized.
- Some species may have hunted in groups, displaying social behavior.
- Feathered dinosaurs with curved claws, sharp teeth, and razor-sharp instincts.
Introduction
The video introduces Dromaeosauridae, or raptors, as sleek, fast, and deadly dinosaurs that have become pop culture icons. It mentions that while Velociraptor is famous, its relatives were equally fascinating. Dromaeosauridae means "running lizards" and describes a family of bird-like meat-eating dinosaurs that flourished during the Cretaceous period. These dinosaurs varied in size, were feathered, and used their stiff tails for balance while hunting. Some scientists believe they may have hunted in groups. Fossils have been found worldwide, mainly from the Cretaceous period, with some evidence suggesting they existed as far back as the Jurassic period. The video promises to explore 16 different members of this group.
Deinonychus
Deinonychus is described as the dinosaur that inspired the raptors in Jurassic Park. It lived in North America during the early Cretaceous period, around 115 to 108 million years ago, in a landscape of forests, flood plains, and an inland sea. Deinonychus belongs to the theropod group, specifically the Dromaeosauridae family, known for bird-like features such as lightweight bones and killer claws. It was about 3 meters (9.8 feet) long and weighed around 100 kg (220 lbs), with a stiffened tail for balance and a curved claw on each foot measuring about 12 cm (4.7 inches) long, used for slashing prey. It likely had feathers for insulation and a high brain-to-body ratio, suggesting intelligence. Some evidence suggests Deinonychus may have lived and hunted in groups, reaching adulthood in about 3 to 4 years. It hunted Tenontosaurus and other available prey. Fossil footprints suggest they traveled in groups, indicating social behavior.
Utahraptor
Utahraptor is an extraordinary predator about the size of a bear, with fossils found exclusively in Grand County, Utah. It lived around 135 million years ago during the early Cretaceous period. It was larger than Velociraptor, with a powerful build, broad skull, and large, curved claws. Utahraptor was likely an ambush hunter, targeting large herbivores like Iguanadons and Ankylosaurs. It was not as fast as smaller dromaeosaurs but still faster than sauropods. A fossil site discovered in 2001 revealed the remains of at least seven Utahraptor individuals, including adults, juveniles, and a hatchling, along with fossils of an Iguanadon. This site is believed to be a predator trap, where Utahraptors became stuck while trying to feed on a herbivore in quicksand. The preservation of multiple individuals together suggests possible group behavior and parental care.
Velociraptor
Velociraptor, meaning "swift thief," was a small, fast, and sharp-clawed dinosaur that lived in Asia during the late Cretaceous period, around 75 to 71 million years ago. Two recognized species are Velociraptor mongoliensis and Velociraptor osmolskai. Unlike its Hollywood depiction, the real Velociraptor was about the size of a large turkey, measuring 1.5 to 2 meters long and weighing 14 to 20 kg. It had a long, stiffened tail for balance and a large curved claw on each second toe. Evidence suggests Velociraptor was feathered, with quill knobs on a fossilized arm bone indicating the presence of large wing feathers. Its head was packed with sharp serrated teeth, and its wrist structure was similar to modern birds. Fossil discoveries, including one showing a Velociraptor locked in battle with a Protoceratops, provide detailed insights into its life. Research indicates it had impressive hearing and was likely warm-blooded to some degree, with a metabolism possibly lower than modern warm-blooded animals. Studies of its nasal cavity suggest it did not have the same advanced temperature control system as modern warm-blooded animals.
Dromaeosaurus
Dromaeosaurus, meaning "running lizard," lived during the late Cretaceous period, around 80 to 69 million years ago, in Alberta, Canada, and the western United States. The type species is Dromaeosaurus albertensis. Despite being featured in dinosaur books and museum displays, actual fossils of Dromaeosaurus are rare. The first remains were discovered in 1914, including a partial skull, mandibles, and foot bones. Dromaeosaurus was a medium-sized carnivore, around 2 meters long and weighing 16 kg, with sharp teeth and a sickle claw on each foot. It had a robust skull with a deep snout and large curved teeth. Originally classified within the Deinodontidae, it was later recognized as closer to Velociraptor and Deinonychus. Dromaeosaurus had a strong bite and likely preferred larger prey, similar to Gorgosaurus. While there is no definitive evidence, studies suggest it was likely diurnal, adapted to hunting during the day.
Austroraptor
Austroraptor is a dromaeosaurid theropod that lived in Argentina during the late Cretaceous period. It was a large dromaeosaur, measuring about 5 to 6 meters long and weighing 300 to 520 kg. The first specimen, Austroraptor cabazai, was discovered in 2002. One of the most interesting features of Austroraptor is its skull, which is low and elongated, measuring about 70 cm. It had conical, non-serrated teeth similar to those of Spinosaurids. Austroraptor also had unusual toes, with the fourth toe much wider than the second. Its forelimbs were relatively short, similar to other dromaeosaurs like Chanuraptor and Mahakala. Austroraptor was likely built for speed and endurance, suggesting it was a fast, agile predator, likely hunting small, fast prey. Its teeth suggest it might have preyed on larger animals, possibly even fish. Austroraptor helps understand the diversity of theropod evolution in the southern hemisphere, likely playing the role of an apex predator.
Adasaurus
Adasaurus, meaning "evil lizard," is a dinosaur from the late Cretaceous period, about 70 million years ago, found in Asia. It was around 2.4 to 3.5 meters long and weighed between 36 to 87 kg. Unlike other dromaeosaurs, it had a smaller, more blunt sickle claw, suggesting it didn't use its claws in the same way. It also had a recurved lacrimal bone, a feature shared with Austroraptor. Adasaurus mongoliensis was named in 1983 after the region where the fossils were discovered. Initially placed in the dromaeosaur group known for deep jaw types, later revisions placed it in Velociraptorinae. The skull structure hints at a different hunting strategy than other dromaeosaurs. Some paleontologists think dromaeosaurids like Adasaurus might have hunted like modern birds of prey, using their claws to pin down smaller prey. It shared its world with other dinosaurs like Tarbosaurus and smaller herbivores.
Dakotaraptor
Dakotaraptor steini, meaning "thief from Dakota," is a large dromaeosaur from the end of the age of dinosaurs, discovered in South Dakota. The species was officially named in 2015. If Dakotaraptor was a raptor, it was a large one, stretching about 5.5 meters long and weighing between 220 and 350 kg. It had a leaner, more agile build than Utahraptor, with long legs built for speed. The foot claws were large, with the second toe claw measuring about 24 cm along the curve. One of the most exciting discoveries was its wings, with bones showing clear evidence of large quill knobs, indicating prominent feathers. Even though Dakotaraptor was too big to fly, it's the largest known dromaeosaur with confirmed wing feathers. These feathers could have been used for display, mating rituals, or balance. Some researchers consider Dakotaraptor a possible chimera, a fossil mashup of more than one species, which could mean it doesn't belong squarely in the Dromaeosaurid family.
Atrociraptor
Atrociraptor marshalli, meaning "savage thief," was a small raptor that lived during the late Cretaceous in Alberta, Canada, around 72 million years ago. The holotype fossil, a partial skull, was discovered in 1995. Atrociraptor was about 1.8 to 2 meters long and weighed around 15 kg. It had feathers, long arms, a stiffened tail, and a curved claw on each second toe. It had a deeper snout than most of its cousins, and its teeth were sharply tilted backward and nearly all the same size. The front of the upper jaw was taller than it was long, and it had unique openings in the maxilla. The teeth were tightly packed and serrated on both edges. More recent research suggests it fits better in a group called Saurornitholestinae. The deep snout might point to specialized feeding habits. The original fossil came from the Horse Thief Member, a humid, low-lying region filled with standing water. Isolated teeth from other parts of the formation have been linked to Atrociraptor, suggesting it stuck around for at least 2 million years, adapting as the landscape changed.
Halszkaraptor
Halszkaraptor escuilliei is one of the strangest dinosaurs discovered, found in Mongolia and lived during the late Cretaceous. It has features suggesting it might have been semi-aquatic. The main fossil has traits expected in animals that spend time in the water, sparking debate about whether it paddled around in lakes or stayed on dry land. Halszkaraptor is part of a group of early raptors called Halszkaraptorinae. The fossil was illegally collected before 2011 and passed through private hands before ending up with researchers in Belgium in 2015. They used synretron scans to examine the fossil, finding it mostly intact. The fossil dates back around 75 million years. The dino was about the size of a duck, with a long neck, a wide, flat snout, and many teeth. Its nostrils were pushed back and pointed slightly upward, and its snout was covered in tiny nerve and blood vessel channels, similar to crocodiles. Researchers suggested Halszkaraptor was a semi-aquatic predator with powerful back legs, smaller forelimbs, and a short tail. However, some researchers have raised doubts about whether its anatomy really supported an aquatic lifestyle.
Achillobator
Achillobator meaning "Achilles hero" was a large ground-dwelling predator from the late Cretaceous, around 96 to 89 million years ago, found in Mongolia's Bayan Shireh Formation. It is the first and largest of its kind discovered there. The only known species is Achillobator giganticus. This dinosaur was a hefty bipedal carnivore measuring about 4.5 to 5 meters long and weighing between 250 and 350 kg. It was built stocky with a deep body and robust legs. Unlike other dromaeosaurs, Achillobator had short arms, a powerful sickle claw on each second toe, and a robust skeleton. It likely hunted larger prey using those claws. Achillobator belongs to the Dromaeosauridae family, specifically the Udromeosaurid group. Its anatomy suggested it wasn't built for sprinting but was suited for hunting larger, slower prey. The pelvic girdle of Achillobator also stood out with primitive features. The skull was large with a robust and deep maxilla. The structure of its hind limbs and pelvis suggested it wasn't an ultra-fast runner. Researchers proposed that dromaeosaurs could have used their sickle claws to leap on prey, immobilize it, and feed on it while still alive. The remains of Achillobator were discovered in an area with semi-arid river environments.
Microraptor
Microraptor is a dinosaur that offers a glimpse into the evolution of flight. This small four-winged dromaeosaur lived during the early Cretaceous, around 125 to 120 million years ago, and was first discovered in Liaoning, China. Recent studies suggest that the initially described three species are variations of one species, Microraptor zhaoianus. One of the most remarkable aspects of Microraptor is its extensive feather coverage, extending not only to its arms and tail but also to its legs, forming a unique four-winged body. In 2003, paleontologist Xu Xing described the first specimen as a four-winged dinosaur, speculating that it could glide using all four limbs. Further studies proposed that Microraptor may have been capable of powered flight. Microraptor was small, with a wingspan of around 88 to 94 cm and weighed only 0.5 to 1.4 kg. It was one of the most abundant non-avian dinosaurs in its ecosystem. Studies of its fossilized melanosomes suggest Microraptor had glossy iridescent feathers. It had four wings, one on each forelimb and hind limb, with the hind wings attached to the feet. Some scientists initially thought it was a glider, but studies of its skeletal structure suggested it wasn't as specialized for climbing. Microraptor was an opportunistic feeder, preying on a variety of animals, including small mammals and fish. Studies of Microraptor's eye structure suggest it may have been nocturnal.
Acheroraptor
Acheroraptor lived in the Late Cretaceous period, around 66 million years ago, in the Hell Creek Formation in Montana, just before the asteroid impact. Acheroraptor is one of the youngest dromaeosaurs and a close relative of Velociraptor. The name Acheroraptor comes from Greek mythology, meaning the underworld, and raptor is Latin for thief. The species name temertyorum honors a couple who supported the Royal Ontario Museum, where the fossils are kept. The main fossil, a specimen with a complete right maxilla and some teeth, was discovered in 2009. Research showed it was likely related to other raptors in the velociraptor group. Its jaws were built for quick slashing bites, suggesting it hunted smaller prey using speed and agility. Acheroraptor is the youngest known dromaeosaur, living just before the mass extinction. The Hell Creek Formation was home to famous species like Tyrannosaurus and Triceratops, along with other raptors like Dakotaraptor. The formation was a diverse ecosystem with theropods, ornithomimids, birds, herbivores, and mammals. Acheroraptor is an important part of understanding dinosaurs just before the extinction event.
Linheraptor
Linheraptor was a bird-like predator that roamed what's now Inner Mongolia, China, during the Late Cretaceous. This raptor was part of the same group as Velociraptor. It was just under 2 meters long and weighed around 25 kilos, built for speed and agility. The fossil was dug up in 2008, and the skeleton they found was nearly complete and still articulated. It came from the Wulansuhai Formation, similar to Mongolia's Djadokhta Formation. Linheraptor exquisitus was officially named in 2010. The name Linheraptor comes from the Linhe district where it was discovered, and exquisitus refers to how well-preserved the fossil is. Linheraptor had a long curved neck, sharp teeth, a stiff tail for balance, and sickle claws on each foot. It was bipedal and built for the chase. It was most closely related to Tsaagan mangas, sharing features in the skull. Some researchers think Linheraptor might actually be the same dino as Tsaagan.
Natovenator
Natovenator polyodontus, meaning "swimming hunter with many teeth," might have been built for the water. Discovered in the Barun Goyot Formation of Mongolia's Ömnögovi Province, Natovenator comes from a stretch of ancient Earth that used to be a dusty flood plain scattered with lakes and streams. The fossil itself is beautifully preserved, almost the full skeleton with a nearly complete skull still in place. The full reveal came in 2022. It added fuel to a debate about whether some raptors were actually semi-aquatic. Natovenator was a lightweight, only about 70 cm long and weighing just 300 g, about the size of a pigeon. It had a long neck, a skinny snout, and a mouth lined with 13 sharp teeth in the premaxilla alone. The upper jaw had a long groove flanked by ridges, possibly linked to a sensitive whisker-like system for detecting movement underwater. The ribs pointed backwards, giving its body a streamlined profile. Its arms might have been shaped to help with paddling. Paleontologist Gregory Scott Paul compared it to modern waterfowl. The vertebrae lacked air sacks, and the structure of the spine showed similarities to birds built for diving. Its nostrils sat farther back on the skull. Researchers placed Natovenator as a fairly advanced halszkaraptorine. The way its teeth were replaced more slowly in the front of the mouth could have allowed it to maintain a full set of large catching teeth at all times.
Bambiraptor
The nearly complete skeleton of a tiny dinosaur was found sticking out of a Montana hillside in 1995. The skeleton was about 95% complete, small, bird-like, and fast-looking. It had long arms, grasping fingers, and a skull that looked more like a bird's than a reptile's. It was dubbed the Rosetta Stone of small theropods. In 2000, it was officially named Bambiraptor feinbergi. Bambi for its youth, Raptor for its predatory nature, and Feinbergi in honor of the Feinberg family. Bambiraptor raised questions about whether it was its own species or just a juvenile Saurornitholestes. What made Bambiraptor stand out was its brain. Despite its small size, it had a relatively large brain, especially in areas tied to agility and coordination. Some scientists think it may have lived in trees. One study even suggested it had opposable fingers. Most paleontologists agree Bambiraptor was feathered. It likely darted through ancient forests like a tiny sharp-clawed squirrelhawk.
Zhenyuanlong
Zhenyuanlong suni is a dromaeosaur from early Cretaceous China that looked like a bird of prey but was grounded for life. It lived about 125 million years ago. The fossil, described in 2015, revealed a nearly complete skeleton with extraordinary preservation, including feathers. Zhenyuanlong had broad veined wings with primaries, secondaries, and coverts arranged much like in modern birds. Its tail was decked out in long, stiff feathers, and it even had a fluffy covering of filaments across its body. It would have resembled a giant bird more than a classic dinosaur. But it was too big to fly, with short arms and a heavy build. Zhenyuanlong is the first large dromaeosaur known to possess such complex flight-grade feathers. Its anatomy suggests it wasn't built for flying, yet its plumage was far from primitive. One possibility is that it descended from smaller flight-capable ancestors and eventually lost the ability to fly. Alternatively, the wings may have served other purposes, such as courtship displays or egg protection. It had unusually short forelimbs and very thin arm bones. Its feathers weren't used for flight, making Zhenyuanlong a striking example of how feathers evolved for functions beyond flying.
