We are continuing our Dinosaur Unit study. Today, we are learning about dinosaur fossils and foot-prints hands-on. My children love modeling dough, especially three pounds of it! (We are using this dough.) Adrian also likes to engage his animal figurines in play, so today, he is a paleontologist, exploring ancients fossils (even making some) and tracking dinosaurs foot-prints.
Spinosaurus (buy similar here).
This dangerous carnivore weighed several tons and could be up to 17 meters long (that is the size of the sperm whale or almost as long as two school buses!) The Spinosaurus had many sharp straight teeth in its crocodile-like mouth. He was a vicious predator, and his meals usually consisted of other dinosaurs or fish. Scientists think that the smartly designed sail on his back fulfilled several functions: it possibly helped the cold-blooded dinosaurs to vital temperature regulation by collecting or distributing heat; it also might have served to impress potential mating partners.
The skeleton of Spinosaurus was easy to identify by its sailed-back bone. (We are using these assorted dinosaur fossil skeletons.)
We also discussed how fossils are "made" and preserved. As sediment covers the remains of an animal, the parts of the animals that did not rot (likes bones and teeth) were encased in the newly-formed sediment, turning into fossils over time. However, as the bone slowly decayed, water infused with minerals seeped into the bone and replaced the chemicals in the bone with rock-like minerals. This process of fossilization results in a heavy, rock-like copy of the original object – a fossil, which has the same shape as the original object, but is chemically more like a rock!
Adrian is using these ancient fossils which include ten sculpted miniatures, including a Dino Footprint, Giant Crab, Ammonite, Raptor Claw, Fossilized Frog, Trilobite, T-Rex Tooth, Fossilized Fish, Dino Skin, and Sea Scorpion.
Triceratops (buy here) lived in the late Cretaceous Period (around 65 million years ago), and although appearing threatening, Triceratops was harmless as it fed on plants and trees. The name ‘Triceratops’ comes from the Greek language, with ‘tri’ meaning three and ‘keratops’ meaning horned face. It needed its three horns to protect itself from T.Rex, who lived during the same time period. As a herbivore, the front part of its jaw was shaped like a parrot's beak which it used to tear apart the plants it ate. The three horns were made of keratin, the same protein fingernails and hair are made of. The horns over its eyes were nearly a meter long. Because its head weighed as much as a small car and made up almost one-third of its body, it also had a very heavy tail to keep its ten-meter long body in balance. Its legs were very strong, like those of a modern elephant.
Triceratops, with its three horns and bony frill around the back of its head, was also easy for Adrian to match to its "fossilized" skeleton.
Brachiosaurus – Adrian's favorite! (Buy here.)
The Brachiosaurus was a herbivore (plant eater) and lived in North America. With chisel-like teeth and a very sharp sense of smell, this plant-eater always found enough to eat. Unlike most other dinosaurs, the Brachiosaurus' front legs were longer than its hind legs, which made it easier for this herbivore to reach its food. As 12-17-meter-high sauropods that specialized in grazing on the treetops, Brachiosaurus could effortlessly harvest cones and fresh leaves no other dinosaur can reach. This giant was feeding almost constantly to sustain its enormous bulk. Standing nearly 40-50 ft. tall/ over 6 metres, as tall as a three-to-four story building, measuring 90 ft. long/23-27 metres, as long as two buses, and weighing 70-90 tons, he was enormous sauropods, thus making Brachiosaurus the largest land animal that has ever existed, at least during their time. For a while, it was considered the biggest prehistoric animal on Earth, but this title belongs to its cousins the Titanosaurs and possibly the Diplodocoids. However, Brachiosaurus was the largest animal that ever walked North America. There is even an asteroid that was named after him.
This Tyrannosaurus-Rex is so detailed – he even has a movable lower jaw! (Buy here.)
Tyrannosaurus’ comes from the Greek words meaning ‘tyrant lizard’, while the word ‘rex’ means ‘king’ in Latin. T-Rex lived in an area of the Earth that now makes up western North America in the late Cretaceous Period, around 66 million years ago. The 13 meter long Tyrannosaurus Rex was a two-legged predatory dinosaur. Although the T-Rex looked quite threatening, it could hardly use its front legs armed with just two claws since they did not even reach his mouth. It had more than 50 teeth measuring more than 15 cm in length, which it used not for chewing but rather for tearing since it swallowed its food in large chunks. To improve depth-perception when searching for food, the eyes of the T-Rex were oriented toward the front such that the fields of vision of both eyes overlapped.
T-Rex walked on two legs, balancing its huge head with a long and heavy tail that sometimes contained over 40 vertebrae. He had small arms that were extremely powerful and featured two clawed fingers, however, the size would have made it hard to grip prey, suggesting that T.Rex may have been a scavenger. On the other hand, evidence in favor of it being a predator includes its forward pointing eyes, which give better depth perception and make it easier to hunt. So, did Tyrannosaurus Rex use its stunted arms to push itself off the ground after restful naps, or to clasp struggling prey close to its chest? Or is it possible that this predator's arms were completely useless, and would have disappeared entirely (as happened with snakes) after another few million years of evolution? No one has a clue. However, Adrian could match its skeleton due to this obvious attribution.
To learn more about our Dinosaur friends, read a post about our Dinosaur Box here.
p.s. Read here our Identifying Animal Tracks in "snow" ❄️ dough post (similar activity, but with forest animals).