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Photos: Dinosaur Nest Fossil
Yesterday I blogged about a fossil dinosaur nest that contains the remains of two unhatched dinosaur eggs, a dinosaur hatchling and an ancient snake caught in the act of raiding the nest. You can now get a closer glimpse of that fossil here. Photos: Dinosaur Nest Fossil originally appeared on About.com Animals / Wildlife on Friday, April 16th, 2010 at 10:55:20. Permalink | Comment | Email this
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Ancient Snake Dined on Dinos
 ↑ Click to enlarge image
A fossil unearthed from a remote corner of western India reads like an ancient crime scene. The fossil depicts a dinosaur nest containing two unhatched dinosaur eggs and the broken pieces of shell from a third egg. Next to the shattered shell lies the remains of a hatchling dinosaur. The fossil also features the remnants of a rather more sinister creature: an ancient snake lies coiled around the broken egg, as if caught in the act of raiding the nest.
The fossil, originally discovered in 1984, is described by Jeffrey Wilson from the University of Michigan Museum of Paleontology and his colleagues in a paper published in the journal PLoS Biology.
Read more...Ancient Snake Dined on Dinos originally appeared on About.com Animals / Wildlife on Thursday, April 15th, 2010 at 10:07:22. Permalink | Comment | Email this
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Photos: Charles Darwin Photo Contest Winners
The Guardian hosted a photographic competition in celebration of the 200th anniversary of the birth of Charles Darwin (last year). You can see the winners of that competition here. The photo contest was organized by the Horniman Museum, the Grant Museum of Zoology and the Society of Biology and features stunning images of tree frogs, orang-utans, spiders, crocodile fish and much more. Photos: Charles Darwin Photo Contest Winners originally appeared on About.com Animals / Wildlife on Wednesday, April 14th, 2010 at 18:55:11. Permalink | Comment | Email this
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What is a Missing Link?
The term "missing link" is terribly misleading, yet it is used so often that it is difficult to ignore. When used with caution, it can communicate the context of a particular fossil find. But when used to imply that the fossil record is a long chain of related organisms, the term missing link is guaranteed to make palaeontologists cringe.
To understand why the term missing link is so often misused, let's first consider the fossil record and what it tells us about past life forms. Every fossil that is discovered was once a living organism. That organism was one individual within a population--one organism within generations of populations. A fossil is a pinpoint of evidence at the tip of an evolutionary branch, it's like a leaf on a tree. A fossil is an end point, not a link in a chain.
We have no way of knowing whether any single fossil is the direct ancestor of any other fossil or living animal. The fossil record offers us no proof of direct ancestory. Evolutionary trees are not genealogies. Their stems and branches represent relationships between entire groups of animals, or clades, not relationships between individuals.
So a single fossil is not a link in a chain. It represents one of many individuals of its kind and its significance comes from an analysis of how it resembles and differs from its nearest relatives on the evolutionary tree. A single fossil can never fully bridge any gap in the evolutionary tree.
The reality is that there are gaps in the evolutionary tree, some bigger than others. When fossils are discovered that help to reduce such gaps, they are better be described as "transitional fossils", not "missing links". But if the term "missing link" is to be used, it should be made clear that the term refers to a fossil that helps us to better describe the transition between ancestral organisms, not any direct link they share. What is a Missing Link? originally appeared on About.com Animals / Wildlife on Saturday, April 10th, 2010 at 23:20:50. Permalink | Comment | Email this
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Cool Chameleons Don't Miss Meals
For cold-blooded animals, the colder it gets—the harder life gets. As temperatures fall, lizards sprint slower, fish swim slower, and frogs jump shorter distances. Life-sustaining skills such as outrunning predators and foraging for food become insurmountable challenges. So it's not surprising that most cold-blooded animals, also known as ectotherms, remain inactive during the cooler parts of the day or avoid frosty habitats altogether. Most cold-blooded animals that is, except for chameleons.
Read more...Cool Chameleons Don't Miss Meals originally appeared on About.com Animals / Wildlife on Tuesday, March 30th, 2010 at 12:11:37. Permalink | Comment | Email this
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Anoles Sidestep Battle of the Sexes
Male and female brown anoles are embroiled in an ongoing genetic tug-of-war. On average, male anoles are 30% longer and 150% heftier than their female counterparts. This difference in stature among the sexes is a form of sexual dimorphism and it means that when it comes to producing offspring, brown anoles may be vulnerable to a phenomenon known as 'sexual conflict'.
Read more...Anoles Sidestep Battle of the Sexes originally appeared on About.com Animals / Wildlife on Tuesday, March 16th, 2010 at 14:05:44. Permalink | Comment | Email this
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The Message Is in the Egg
Before they've hatched, canary chicks receive clues about what life will be like for them outside the egg. Chemicals produced by the mother serve as messages to a developing chick that describe the kind of parenting that awaits it as a nestling. The chick interprets these messages and, after hatching, develops the behavior most appropriate for the conditions it will face.
Read more...The Message Is in the Egg originally appeared on About.com Animals / Wildlife on Monday, March 15th, 2010 at 08:20:16. Permalink | Comment | Email this
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State of the Birds Report Published
Global climate change will have a significant impact on birds in both terrestrial and aquatic habitats according to a report published by the Interior Department. The report, The State of the Birds, examines the threats facing birds that inhabit the United States and assesses the risks they face. The report indicates that the bird species most vulnerable to climate change are those that rely most on the ocean or inhabit the Hawaiian Islands.
State of the Birds Report Published originally appeared on About.com Animals / Wildlife on Sunday, March 14th, 2010 at 15:50:37. Permalink | Comment | Email this
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Giant Filter Feeders of the Jurassic
Basking sharks, manta rays, whale sharks, and baleen whales all have one thing in common: their eating habits. These animals are marine filter feeders. They get their meals by straining tiny organisms from the seas in which they swim. Basking sharks, manta rays, and whale sharks employ gill rakers to sift their food from the water. Baleen whales filter food from water using, as their name implies, a keratinous structure known as baleen.
Read more...Giant Filter Feeders of the Jurassic originally appeared on About.com Animals / Wildlife on Tuesday, March 9th, 2010 at 17:33:08. Permalink | Comment | Email this
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