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Dinosaurs
Dinosaurs are a prehistoric species that lived on Earth from 230 to 65 million years ago.
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Literally, it's the evolution of living things. Generally it's refered to simply as evolution.
The short answer is evolution is the gradual shift of living things through natural selection.
A simple way to visualise this is imagining a single creature and it's children. Obviously, the children don't look exactly like the parent (Variation), so one will be taller, one stronger, one faster, and so on. As those children grow up, the ones with an advantage do better. The faster child can outrun a predator and survive, the taller one can reach food the others couldn't, and so on. This advantage means the 'better' child is more likely to live long enough to breed.
For our example, we'll say the tall child has an advantage. Food is higher up, and he has an easier time getting to it. That means he spends less time gathering food, and more time trying to breed. The shorter ones spend their time trying to eat enough to survive, and don't get a chance to breed (or aren't strong enough to get a mate).
These grandchildren of the original will then look like their father who is slightly taller. Those children will also have variation... some will be shorter, and some will be even taller. Those even taller kids now have an advantage. And so on, and so on. Each family of the animal looks pretty much the same as it's parents but over the course of thousands and thousands of generations, the result can be totally different.
This example is a huge simplification of evolution, however it serves to convey the idea. If you are interested in biology and evolution, please feel free to read any of the countless articles online about the topic in greater detail.
In prehistoric times what creatures lived in Nevada?
in prehistoric times, ichthyosaurs lived in Nevada.
plant and anamels
Did water dinosaurs go extinct?
There were no purely aquatic dinosaurs. It is generally assumed that all dinosaurs were terrestrial but there may have been semi aquatic dinosaurs that spent some time in water and some time on land.
The marine reptiles generally assumed to be dinosaurs were in fact only distantly related.
The sauria clade of reptiles would evolve into 4 main orders of reptile. Ichthyosauria, Sauroterygia, Lepidosauromorpha and Archosauromorpha.
The Archosauromorpha order of reptiles evolved from sauria about 260 million years ago in the late permian period. They would later evolve into crocodiles, dinosaurs/birds and pterasaurs. Dinosaurs did not evolve until the late Triassic period about 230 million years ago. All dinosaurs apart from avian dinosaurs became extinct 65.5 million years ago. The only "dinosaurs" alive today are the birds.
The Ichthyoaurs were the 1st class of reptiles to adapt to an aquatic lifestyle. Ichthyosaurias evolved from sauria about 245 million years ago. They could be found in the ocean for the next 155 million years. They became extinct 90 million years ago about 15 million years before the non avian dinosaurs.
The Sauroterygia were thought to evolved from sauria about 245 million years ago. They were mostly semi aquatic reptiles all but the pleisoaurs became extinct during the extinction event at the end of the Triassic period. The pleisosaurs are thought to be mainly aquatic but died out 65.5 million years ago during the K-T extinction event. The largest known carnivour was a pleisosaur, Lipleurodon.
The Lepidosauromporpha were thought to have evolved from saurai again 240 million years ago. They are very closely related to sauroterygiae. They would go on to evolve into many of the modern day reptiles such as lizards, snakes & turtles. One family that evolved from this order of reptiles was the mosasaurs. Mosasaurs did not evolve until the early Cretaceous Period about 140 million years ago and were to become extinct at the end of the Cretaceous along with non-avian dinosaurs, pterasaurs and pleisosaurs.
Just a sub note that if you really want to see an aquatic dinosaur then go to the zoo and watch the penguins. Birds are so closely related to dinosaurs and share such similar morphology that they are now generally considered as avian dinosaurs.
A Tyrannosaurus rex's foot was quite large, measuring about 3 feet (0.9 meters) long and 2 feet (0.6 meters) wide. The foot had three main toes, each equipped with sharp claws, which helped the dinosaur support its massive weight and capture prey. Overall, the size of a T. rex foot contributed to its formidable presence as one of the largest land predators of its time.
Why did dinosaur bones stay preseved in the dirt?
Dinosaur fossils have been preserved because they don't decompose quickly. Then, they were buried quickly by natural causes (IE, flash floods, etc), which protected them from the elements and further slowed the process of decomposition. Then, rain leaked through the soil, leaching out some of the minerals in the bone and replacing them with others. Eventually, the new minerals completely replaced the old ones, and pressure from the increasing amount of soil and rocks above compressed and hardened the fossils. The formed fossils were now protected because they were surrounded by the soil they had been buried in, which had now turned into stone, too.
Can you get sick if you ate something a mouse ate?
Absolutely but not definitely. People are probably exposed to much more bacteria in their day to day lives from rodents and insects than they realize and probably have had some immune response to the antigens to which they have been exposed.
Who do you tell if you find a dinosaur bone?
You see if you find a dinosaur bone you could either feed it to your dog, or just put it in some asain retarded soup.( i heard it makes the sh*t taste better
What was Earth's surface like 1.6 million years ago?
Earth's surface changed many times during the Precambrian (which is the time between when Earth first formed and when the Cambrian began, and makes up 7/8 of Earth's history).
In the beginning, Earth was a giant mass of magma, but it eventually cooled enough to have a stable crust. Then, water vapor in the atmosphere condensed and fell as rain, eventually covering the Earth in a giant ocean, which was green because of dissolved iron.
Life, (in the form of simple bacteria), first evolved about 3.5 billion years ago. However, it did not change Earth's climate or the appearance of its surface until the first photosynthesizing organisms (which were cyanobacteria) evolved at least 2.8 billion years ago. The oxygen that they produced first oxidized the iron in the oceans, which made the iron sink, and the oceans became blue, as they are today. Eventually, carbon dioxide levels became so low, and oxygen levels so high, that the Earth underwent such dramatic cooling that ice covered the ocean all the way to the Equator for millions of years.
Meanwhile, continents formed, joined together into supercontinents, and then broke back up again. However, the continents were completely different in both shape and position during the Precambrian than they are today.
Lastly, it is important to note that there is no evidence of any form of life on land, nor of multicellular organisms, until after the Precambrian (e.g., the Cambrian).
What type human lived 25 million years ago?
25 million years ago, humans did not exist.
Australopithecus (the earliest human) evolved about 3.75 million years ago.
What was life like 100 million years ago?
About 100 million years ago, during the late Cretaceous period, Earth was dominated by dinosaurs, which roamed diverse habitats ranging from lush forests to arid plains. The climate was generally warm and humid, with higher sea levels creating expansive shallow seas and rich marine life. Flowering plants began to emerge, contributing to the evolution of various ecosystems. Insects, including early bees and butterflies, thrived, playing crucial roles in pollination and food webs.
What kind of deers are extinct?
megaloceros aka the Irish elk
Candiacervus
Libralces
and Stag-moose are extinct deer
What was the full name of Stellaraptor?
The full name of Stellaraptor was *Stellaraptor Carnifasus* *stel-la-rap-tor* *car-nif-a-sus* Meaning *Single Hunting Raptor of Stealth*
How are artists able to draw models or pictures of dinosaurs when they are already extinct?
Artists can only guess what dinosaurs looked like. They probably use hints such as a dinosaur's skeletal structure, teeth, etc.
Do dinosaurs live in cold or hot regions?
They lived all over the world. Realize, though, that in Dinosaur Days, there weren't any "cold" regions as we know of them today. Plants grew at the South Pole. Most dinosaurs never saw snow.
