Tiniest Meat-Eating Dino Was Size of a Chicken

Tiniest Meat-Eating Dino Was Size of a Chicken

www.washingtonpost.com

-- Scientists have identified the smallest known meat-eating dinosaurs to have roamed areas of North America 75 million years ago.

Fossils of the dinosaur, which was the size of a small chicken, were found in Canada in 1982 but not studied until recently.

(visit the link for the full news article)

How did they date this hing at 75 million years, carbon dating is only accurate to 4000 years or so. How do they know it was a meat eater? Did hey find the contents of its stomach too? Lots of guessing still going on in the dinosaur world but none the less an interesting find.

Anyone consider it was a baby? You know how babies are smaller versions of their parents, maybe this was a baby dinosaur that had not yet reached full size when the flood happened and killed them all off...

www.washingtonpost.com
(visit the link for the full news article)

Were these not in Jurassic Park, the ones that ate the fat guy driving the jeep?

Guess I should of read the article first....

[edit on 18-3-2009 by NateNute]

1. The oldest method is stratigraphy, studying how deeply a fossil is buried. Dinosaur fossils are usually found in sedimentary rock. Sedimentary rock layers (strata) are formed episodically as earth is deposited horizontally over time. Newer layers are formed on top of older layers, pressurizing them into rocks. Paleontologists can estimate the amount of time that has passed since the stratum containing the fossil was formed. Generally, deeper rocks and fossils are older than those found above them.

2. Observations of the fluctuations of the Earth's magnetic field, which leaves different magnetic fields in rocks from different geological eras.

3. Dating a fossil in terms of approximately how many years old it is can be possible using radioisotope-dating of igneous rocks found near the fossil. Unstable radioactive isotopes of elements, such as Uranium-235, decay at constant, known rates over time (its half-life, which is over 700 million years). An accurate estimate of the rock's age can be determined by examining the ratios of the remaining radioactive element and its daughters. For example, when lava cools, it has no lead content but it does contain some radioactive Uranium (U-235). Over time, the unstable radioactive Uranium decays into its daughter, Lead-207, at a constant, known rate (its half-life). By comparing the relative proportion of Uranium-235 and Lead-207, the age of the igneous rock can be determined. Potassium-40 (which decays to argon-40) is also used to date fossils.

The half-life of carbon-14 is 5,568 years. That means that half of the C-14 decays (into nitrogen-14) in 5,568 years. Half of the remaining C-14 decays in the next 5,568 years, etc. This is too short a half-life to date dinosaurs; C-14 dating is useful for dating items up to about 50,000 - 60,000 years ago (useful for dating organiams like Neanderthal man and ice age animals).

Radioisotope dating cannot be used directly on fossils since they don't contain the unstable radioactive isotopes used in the dating process. To determine a fossil's age, igneous layers (volcanic rock) beneath the fossil (predating the fossil) and above it (representing a time after the dinosaur's existence) are dated, resulting in a time-range for the dinosaur's life. Thus, dinosaurs are dated with respect to volcanic eruptions.

4. Looking for index fossils - Certain common fossils are important in determining ancient biological history. These fossil are widely distributed around the Earth but limited in time span. Examples of index fossils include brachiopods (which appeared in the Cambrian period), trilobites (which probably originated in the pre-Cambrian or early Paleozoic and are common throughout the Paleozoic layer - about half of Paleozoic fossils are trilobites), ammonites (from the Triassic and Jurassic periods, and went extinct during the K-T extinction), many nanofossils (microscopic fossils from various eras which are widely distributed, abundant, and time-specific), etc.

Originally posted by NateNute
Were these not in Jurassic Park, the ones that ate the fat guy driving the jeep?

Guess I should of read the article first....

[edit on 18-3-2009 by NateNute]

Fat Guy! Nooooooooooooooooooo!

Seriously though, they were Dilophosaurus, which were actually about 10ft tall. And probably not poisonous. So no.