The Colors of Ancient Sea Reptiles Discovered

STUDY THE PICTURE and TITLE – what do you predict will be explained in this article?

Answer here (2-3 sentences):

(1) Leatherback turtles, and other ancient sea reptiles, had black skin. That’s the conclusion of a new study on three fossilized sea reptiles, in which scientists reconstructed the color of the creatures’ skin by detecting traces of the pigment melanin. The melanin may have been an adaptation for living in cold water and for camouflaging the animals. Colors of ancient animals are usually impossible to tell—skin cannot be preserved over millions and millions of years. Color usually remains a mystery.

(2) Thanks to technology and a little luck, scientist Johan Lindgren and his team have found a solution, revealing reptile colors from as far back as 190 million years ago.“On rare occasions, the fossil record reveals examples of exceptional preservation,” Lindgren wrote.(3) The researchers found that dark smudges on three fossils—an ichthyosaur, a mosasaur, and an ancient leatherback turtle—were examples of such exceptional preservation, possibly the remains of skin tissue.(4) To see if the smudges truly represented reptile skin or were simply bacteria covering the fossils, Lindgren’s team scraped it off with a scalpel and examined its atomic structure. They determined that the tissue contained mostly melanin.

(5) Lindgren’s team concluded that the three reptiles all sported a similar shade of brown/black due to the melanin in their skin. Cool. Why is that significant?For one, the dark color could have provided camouflage in the murky depths where the reptiles lurked.(6) Perhaps more importantly, melanin allows animals to heat themselves faster and to maintain higher body temperature because it absorbs a large amount of sunlight and heat. Think of a drab box turtle basking on a rock at high noon. High melanin content allows them to go into colder water.

(7) Mosasaurs are the stuff of sci-fi imaginations run amok, 60-foot shark eaters that lived around 85 million years ago. Ichthyosaurs were smaller and fishlike, living 100 million years earlier, and the leatherback turtle in the study lived around 55 million years ago.(8) In other words, these beasts evolved similar colors even though they lived millions of years apart.

1. Summarize the story in 2-3 sentences:

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3. What are the two reasons the animals would need melanin and dark skin in the underwater environment?A:

2. UNDERLINE three main ideas in the article.

4. Skin is almost never is found on fossils. What parts of an organism do you think make good fossils?A:

Paleo Dieters Beware — Cavemen Had Cavities Too

STUDY THE PICTURE and TITLE – what do you predict will be explained in this article?

Answer here (2-3 sentences):

(1) A new study finds that prehistoric humans had as many cavities as modern people. Had they existed, we’re betting four out of five Pleistocene dentists would have recommended chewing fewer nuts and acorns.

(2) Tooth cavities in humans have long been associated with eating carbohydrate (sugar) -rich foods. Here’s how it happens: Bits of the carbohydrates get stuck on teeth, creating a happy environment for bacteria, which produce acids that cause tooth decay. Researchers had thought that cavities were tied to the beginning of agriculture and farming, when humans began eating more grains and processing their food more than earlier humans had.

(3) New research suggests, however, that cavities and other forms of oral disease have been a pain in the mouth for our species for much longer. The rate of cavities in teeth from North African hunter-gatherers more than 14,000 years old was close to that of modern industrialized populations chomping on doughnuts and gulping sugary sodas.

(4) Researchers focused on a place in Morocco called Grotte des Pigeons because of its combination of both multiple human burials and middens. The middens are basically trash heaps full of plant and animal material. More than half of adult teeth studied from the site had cavities.

(5) Researchers mostly found Holm oak acorns and Maritime pine nuts as the main edible nuts at this site, though wild oats, pulses and pistachio nuts were also found. Researchers concluded that acorns and pine nuts were a important foods of these hunter-gatherer people.

(6) Acorns and pine nuts, as well as pulses and oats, are high in carbohydrates. Eating them created the perfect environment for decay-causing bacteria in the mouths of the hunter-gatherers. Land snails were another diet staple for the population, and researchers theorized that gritty particles in the snails may have increased tooth wear and accelerated cavity development.

Still, the high rate of cavities came as a surprise to researchers.

1. Summarize the story in 2-3 sentences:

A:

UNDERLINE 2-3 important/ main ideas

2. Knowing about unicellular organisms is important to understand this article. UNDERLINE a section of the story that is an example of this, THEN explain why it is important:

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3. Why were scientists SURPRISED that ancient people had cavities in their teeth like modern humans?

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UNDERLINE a section of the article that supports your answer.

Which article do you think is more relevant to what we are studying in class currently and explain WHY.

Article #1 or #2?

Explain why(2-3 sentences):

Cite a piece of evidence from either article that supports your answer to the above question:Write it here

WHY does this example support your answer?Answer: