However, the dorsal centra of the neotype are greater in length, and thus, while the two specimens seem to scale to similar sizes in several aspects, the neotype ends up somewhat larger than the holotype due to a longer dorsal series.
Certain isolated specimens assigned to S. MSNM v, a This results in an animal about 15 metres long. The length of the element as preserved is 69 cm, broken off through the 17th dentary alveolus. This results in an animal nearly 16 metres long, longer than estimated for MSNM v here despite the shorter dorsal column of the holotype specimen as compared to the neotype.
Missing portions not covered by any documented Spinosaurus material were filled in using Irritator , Sigilmassasaurus , Suchomimus and Baryonyx. Skip to content. Home Skeletal Reconstructions Palaeoart.
Hoping to find dinosaur remains in particular, some diggers have focused their energies on the Kem Kem beds, a sandstone formation between 95 and million years old that starts miles east of Marrakesh and extends miles to the southwest.
The rocks preserve traces of what was once a vast river system where fish the size of cars once swam. When miners come across fossils, they usually sell the bones to a web of wholesalers and exporters. This fossil mining industry provides vital income to thousands in this region, though it operates in a legal and ethical gray area. Locals dig year-round, making them almost certain to find more scientifically valuable specimens than academic paleontologists, who dig only a few weeks a year.
On one such visit to a village outside the town of Erfoud in , Ibrahim—by then a specialist in the Kem Kem beds—met a man who had found bones the scientist later realized might belong to a Spinosaurus. The encounter may as well have been fate. Ibrahim had loved Spinosaurus ever since he was a young boy growing up in Berlin.
A second trip by Ibrahim, Zouhri, and University of Portsmouth paleontologist David Martill in at last led the team to the Kem Kem outcrop where the fossils originated, and they started finding more bone fragments. Their work, published in Science in , declared the Moroccan fossils as a replacement for the original Egyptian ones lost in World War II bombings.
Their reconstruction revealed the creature was 50 feet long when fully grown, longer than an adult T. The study polarized paleontologists. Those researchers thought it likely that Spinosaurus, like other spinosaurids, ate fish by wading into the shallows like grizzly bears and herons.
But based on the incomplete Moroccan remains, could researchers now say for certain that the prehistoric predator did more than its kin and quickly swam after aquatic prey?
If so, how did it move through the water? Still others expressed doubt that the Moroccan bones belonged to a Spinosaurus. While the newfound Moroccan bones were clearly spinosaurid, the number of spinosaurid species in North Africa was, and is, a matter of scientific debate.
Or did they instead belong to a close, but distinct, relative? Seeking to put the controversy to rest, Ibrahim and his colleagues returned to the Moroccan site, with the support of the National Geographic Society, to check for more bones in September Time was of the essence: He had heard from local contacts that commercial fossil diggers were tunneling into nearby hills for bones. The dig started brutally. It broke within minutes. Days were so grueling that several team members were hospitalized once they returned home.
But the promise of discovery kept them going, along with Nutella breaks that temporarily took their minds off the punishing work. The degree heat and arid winds wicked liters of water from my body as we chipped our way through an outcrop marbled like bacon. When the fruits of all this labor were at last laid out on tables back in the Casablanca lab, Ibrahim and his colleagues knew they had something truly remarkable. By the end of alone, the dig team had uncovered more than 30 Spinosaurus tail vertebrae.
Crucially, some of the tail bones neatly match up with illustrations of more fragmentary spinosaurid tail vertebrae that Stromer published in , bolstering the case that a spinosaurid species living in Cretaceous North Africa ranged from Morocco to Egypt. Though digitally modeling animal motion is one of her specialties, Pierce knew that answering the question required dynamic, real-world experiments.
She and her colleague George Lauder , a fish biologist, agreed to join the team. Lauder, sitting at a workbench, reached for an orange plastic sheet—the laser-cut outline of a Spinosaurus tail—and attached it to a metal rod.
He then walked across the lab to what looked like an elaborately built fish tank and mounted the tail inside a tangle of metal beams hanging from the ceiling. Studded with lights, cameras, and sensors, the ensemble can precisely track the aquatic movements of a swimming animal or a swimming robot—and the forces they impart as they move.
As I watched, Lauder lowered the Flapper into the water, and the plastic model Spinosaurus tail attached to it sprang to life with a motion meant to mimic a swimming alligator. These claws were ideal for hooking or slicing slippery prey. A small pelvis and short hind legs with muscular thighs. As in the earliest whales, these adaptations were for paddling in water and differ markedly from other predatory dinosaurs that used two legs to move on land. Particularly dense bones lacking the marrow cavities typical to predatory dinosaurs.
Similar adaptations, which enable buoyancy control, are seen in modern aquatic animals like king penguins. Strong, long-boned feet and long, flat claws.
Unlike other predators, Spinosaurus had feet similar to some shorebirds that stand on or move across soft surfaces rather than perch. In fact, Spinosaurus may have had webbed feet for walking on soft mud or paddling. These bones enabled its tail to bend in a wave-like fashion, similar to tails that help propel some bony fish.
0コメント