Ceratopsian fossil.
New evidence has been discovered supporting the theory that the cause for the extinction of dinosaurs was due to the catastrophic meteor that struck Mexico’s Yucatan peninsula around 65 million years ago. A fossil from what is known as a ceratopsian dinosaur (most likely a Triceratops or a Torosaurus) was discovered in the Hell Creek Formation in south-east Montana. American paleontologists found this 18 inch long horn just 13cm below the famous K-T boundary. The fossil is said to be the youngest dinosaur bone ever found.
The K-T boundary is a layer in the earths crust that paleontologist use to identify the time period of when the meteor struck earth and up until now there has been opposing theories for the reason behind the extinction of dinosaurs. The opposing theory to the idea of the dinosaurs becoming extinct due to the meteor is that dinosaurs were extinct long before the meteor hit. This theory is based on the evidence supported by the fact that there have been no fossils ever found 10 feet below the K-T boundary (also referred to as the “Three- Meter Gap”) . The three-meter gap represents about 100,000 years and the horn was found about 5 inches (13cm) below the K-T boundary. Based on the location of the horn this suggests that the ceratopsian dinosaur was alive and well at least a few thousand years before the impact, making the theory that dinosaurs were extinct long before the meteor strike impossible to believe. Tyler Lyson, a Yale paleontologist and the lead author of the study, now says because of this discovery the three-meter gap no longer exists, and he now refers to the gap as the “13- centimeter gap”.
For further reading:
http://www.ctv.ca/CTVNews/TopStories/20110715/dinosaur-discovery-hell-creek-montana-110716/
http://www.wired.com/wiredscience/2011/07/dinosaur-extinction-fossils/
http://blogs.discovermagazine.com/80beats/2011/07/13/youngest-dinosaur-bone-yet-reawakens-extinction-debate/