The Debate Over Birds and Feathered Dinosaurs

The Debate Over Birds and Feathered Dinosaurs

Because dinosaurs are animals that lived millions of years ago, we are entirely dependent on the fossils that they have left behind for any understanding that we hope to gain. As any paleontologist will tell you, fossil hunting is difficult. There are no certainties, no guarantees. A certain amount of luck is as valuable as any scientific knowledge.

Every so often a discovery is made that attempts to shake up pre-conceived notions of how the dinosaurs actually lived or how they came to be. On June 22, 2000, in Oregon, scientists announced the discovery of the oldest known animal to have feathers. Though no records indicate how the age of the animal was determined, the fossil was dated at 220 million years old. It lived at the time of the very earliest dinosaurs, and about 75 million years before the first known bird.1[1]

The scientists assert that Longisquama insignis is not a dinosaur, and may be one of the earliest bird ancestors. The animal was a small lizard-sized glider, with four legs and feathers on its body. It is believed that the feathers were used for gliding, as the ancient creature lacks the necessary structures for flying.1

Before the announcement of Longisquama, the earliest known animal with feathers was Archaeopteryx, a bird capable of flight that lived roughly 145 million years ago.1 It has been proposed that Archaeopteryx is the intermediary between birds and predatory theropods, such as Deinonychus.2 The discovery that Longisquama had feathers strongly questions the evolutionary origins of Archaeopteryx, and additionally may discredit the belief that it is the link between birds and dinosaurs.

However, th...

... middle of paper ...

...cgi-taf/DynaPage.taf?file=/nature/journal/v408/n6811/full/408428a0_fs.html

5 The Field Museum. (2002). New Species Clarifies Bird-Dinosaur Link. Science Daily [online], 14 Feb 2002. Available at http://www.sciencedaily.com/releases/2002/02/020214080242.htm

6 Monastersky, R. (1998). Feathered Dinosaurs Found in China. Science News Online [online], 27 June 1998. Available at http://www.sciencenews.org/pages/sn_arc98/6_27_98/fob1.htm

7 H, J R. (1995). Are Birds Really Dinosaurs? [online] Available at http://www.ucmp.berkeley.edu/diapsids/avians.html

8 Rusatte, B. (1997). Controversial Fossil Claimed to Sink Dinosaur-Bird Link. [online] Available at http://www.geocities.com/CapeCanaveral/Galaxy/8152/longisquama.html

9 Brett-Surman, M K, et al. Top 10 Misconceptions about Dinosaurs. [online] Available at http://www.nmnh.si.edu/paleo/faq.html