July 27 – We’re Off To See The Lizard

Today’s factismal: Reptiles are found on every continent except Antarctica (and they used to live there!).

If you want to call a group of animals successful, then you have your choice of how to define the term. You can base it on the distribution of the critters: those that live in more places are more successful. Or you can base it on the longevity of the critters’ family tree (what biology wonks call a clade): those that have been around longer are more successful. Or you can base it on all of the other critters that have evolved out of that clade: having more branches on their tree of life makes them more successful.

An alligator in Texas (My camera)

An alligator in Texas
(My camera)

But no matter how you define success, the reptiles have it. They’re found on every continent except Antarctica (they moved away from there when it got too cold), they’ve been around for 312 million years, and their descendants include obvious suspects like crocodiles and turtles, and some not-so-obvious ones like the dinosaurs, the birds, and the mammals.

An iguana in Florida (My camera)

An iguana in Florida
(My camera)

But success has its price. In the case of the reptiles, it means getting pushed out by younger and more vigorous critters, like humans. In Los Angeles and other parts of California, the native lizards have almost entirely disappeared, thanks to changes in the environment caused by building and water use. It has gotten so bad that now researchers are out looking for lizards, and they’d like your help. If you happen to live in Los Angeles (or are just stuck in a tourist trap ☺), then why not give them a hand by reporting any lizards that you see to the RASCals Project at the Los Angeles Natural History Museum:
http://www.nhm.org/site/activities-programs/citizen-science/rascals

May 19 – All The Way Down

Today’s factismal: Galápagos tortoises are an example of island dwarfism.

Quick! What weighs 550 lbs, is big enough to ride on, and is the smallest of its kind? Why, it is the Galápagos Island tortoise. These huge reptiles are amazing animals. They move at a top speed of nearly two miles a day and feed of a wide variety of vegetables (such as cacti and berries) and small animals (such as lizards and fish). Young tortoises will eat more than 1/8th of their body weight each day, turning the excess into fat that they store for food during the lean months. And those lean months can be long, indeed; the Galápagos tortoise can live for a year on the food and water stored in its shell as fat.

A Galápagos tortoise looking for lunch (My camera)

A Galapagos tortoise looking for lunch
(My camera)

But amazing as that is, what is even more amazing is that the Galápagos tortoise is probably the last of its lineage of giant tortoises, all of which were larger than it. Consider the Hesperotestudo crassiscutata, a giant gopher tortoise, which was about twice as big as the Galápagos tortoise and lived in Texas and Central North America until about 12,000 years ago. And then there was Megalochelys atlas; it lived in India and was another tortoise that makes the Galápagos tortoise look like a runt. Let’s not forget the Ninjemys oweni, a spike-covered super tortoise. And if we go back a few million years, there is the great-granddaddy of scary big tortoises, Carbonemys cofrinii. This guy was roughly the size of a Prius and lived on a diet of crocodiles, fish, and molluscs.

This tortoise is looking for lunch in all the wrong places (My camera)

This tortoise is looking for lunch in all the wrong places
(My camera)

Giant tortoises had a survival advantage in a wet world like the Pleistocene. They could jump into the water and survive long ocean voyages until they came to a landing place. Much like a reptilian coconut, they would have used the sea currents to populate islands and new territories. But like the vegetable coconuts, they were too tasty to survive. Other critters would have found them an easy food source. As a result, the mainland tortoises died out as smilodons, cave bears, and hominids munched them into extinction; in the end, only the species that had moved to islands survived.

And those species, including our friend the Galápagos tortoise, suffered the same fate as elephants, hippopotamuses, and even hominids on islands. Each succeeding generation is smaller because the island’s limited resources give a smaller size a survival advantage. In 1964, a biologist came up with the rule that animals that colonize islands tend to either grow larger or smaller to match the resources available on the island. Known as Foster’s Rule, this was a triumph of evolutionary biology. And today we continue to learn about evolution with the help of citizen scientists. One project is the Evolution MegaLab. By counting the number of bands on snail shells, we can see how their predators (thrushes) are forcing snails to change and adapt. To learn more, crawl over to:
http://www.evolutionmegalab.org/en_GB

February 19 – Flipper!

Today’s factismal: The most recently identified ichthyosaur has been named after Mary Anning, who discovered the first ichthyosaur skeleton in 1811.

Quick! What’s sleek and fast in the water, has a long, toothy grin, big flippers, and isn’t a fish? If you said “dolphin”, you’d be right today. But 200 million years ago the answer would have been “ichthyosaur”. That was when these now-extinct swimming reptiles dominated the oceans, noshing on everything from ammonites to turtles to fish to squid. And that last was the favorite meal of the most recently identified ichthyosaur, based on an absolutely amazing fossil in Doncaster Museum and Art Gallery.

A different ichthyosaur (My camera)

A different ichthyosaur
(My camera)

This new/old critter was identified just this year even though the original fossil was found nearly 30 years ago. The delay was partly because there were so many fossils found at the time that it was hard to catalog them properly and partly because it was originally thought to be a plaster copy and not a real fossil. But when the paleontologists got a good look at it, they went ape (or reptile in this case). The stomach contents were clearly visible (a bunch of squid beaks) as were the bones and teeth. Based on careful measurements of the fossil which was compared with more than 1,000 other ichthyosaurs, it was identified as a new species. And, because it was found near where the first ichthyosaur fossil was discovered, this one was named for the person who found the original: Mary Anning. So this one is called ichthyosaurus anningae or “Anning’s swimming lizard”.

The last thing this ammonite saw was an ichthyosaur's mouth (My camera)

The last thing this ammonite saw was an ichthyosaur’s mouth
(My camera)

If you’re a teacher and would like your class to do a bit of fossil hunting, then why not join PaleoQuest? They are looking for folks like you to help them discover shark fossils from the Atlantic coastal plain. Just register with them and they’ll send you a matrix of material. You dig through it and then send them back all of the shark bits you find. The results will be displayed in the Calvert Marine Museum. And if your fossil gets used in a publication, then you’ll actually be named in the paper! For more info, swim over to:
http://paleoquest.org/10.html

September 4 – Turtles all the way down

Today’s factismal: Baby box turtles like to eat insects, slugs, and snails. Adult box turtles like to eat fruits and vegetables.

If you grew up in Oklahoma, Texas, or Louisiana, odds are that you had a box turtle for a pet as a child. And you probably wondered why your little turtle friend would never eat the lettuce that you put out for him. The answer is simple: just like young humans, young box turtles don’t eat their vegetables. Instead, they prefer to munch on insects, slugs, snails, and other turtle junk food. But, as they get older, the box turtle’s diet shifts and they start to eat more plants (probably because the plants can’t run away from them the way that insects do).

A box turtle sits on a rock, contemplating how he got into this predicament (My camera)

A box turtle sits on a rock, contemplating how he got into this predicament
(My camera)

That’s not the only way that box turtles are like people. Box turtles age at about the same rate that people do, too! Most box turtles grow very slowly after they hatch and only reach maturity (read: get ready to date) once they are about ten years old and six inches long. Female box turtles lay one or two clutches of eggs each year, with three to six eggs in each clutch. The adult box turtles then continue to chase plants and each other for the next twenty to forty years; some researchers even report seeing 100 year old box turtles!

But there’s something out there that may keep most box turtles from living that long: people. Many box turtles are taken to sell as pets or food, and others are killed by cars as the turtle crosses the road (Why? To get to the tossed salad!). As a result, the number of box turtles in the wild is shrinking. How far? We’re not sure. And that’s where you come in! If you spot a box turtle in Texas, then please report it to the Texas Nature Trackers: Box Turtle Survey Project. And then reward yourself with a nice, juicy worm! (Or an ice cream cone. Your choice.)
http://www.tpwd.state.tx.us/huntwild/wild/wildlife_diversity/texas_nature_trackers/box_turtle_survey/

July 25 – Hey, Eddie!

Today’s factismal: Reptiles are found on every continent except Antarctica (and they used to live there!).

If you want to call a group of animals successful, then you have your choice of how to define the term. You can base it on the distribution of the critters: those that live in more places are more successful. Or you can base it on the longevity of the critters’ clade: those that have been around longer are more successful. Or you can base it on all of the other critters that have evolved out of that clade: having more branches on their tree of life makes them more successful. But no matter how you define success, the reptiles have it.

An alligator in Texas (My camera)

An alligator in Texas
(My camera)

They are found on every continent except Antarctica and used to live there until it got too cold for them about 15 million years ago. Reptiles are found in a wide variety of environments, from the rocky shores of the Galapagos to the lush rain forests of North America. They eat an incredible variety of foods, from salty seaweed to juicy grubs to each other. And the reptiles have been around for a long, long time; the earliest known reptile lived some 338 million years ago. But most importantly, they gave rise to a wide variety of other types of animals, from the dinosaurs (who gave rise to the birds) to the mammals (who gave rise to us and the internet).

An iguana in Florida (My camera)

An iguana in Florida
(My camera)

But success has its price. In the case of the reptiles, it means getting pushed out by younger and more vigorous critters, like humans. In Los Angeles and other parts of California, the native lizards have almost entirely disappeared, thanks to changes in the environment caused by building and water use. It has gotten so bad that now researchers are out looking for lizards, and they’d like your help. If you happen to live in Los Angeles (or are just stuck in a tourist trap ☺), then why not give them a hand by reporting any lizards that you see to the RASCals Project at the Los Angeles Natural History Museum:
http://www.nhm.org/site/activities-programs/citizen-science/rascals

July 12 – What A Croc!

Today’s factismal: A female Nile crocodile determines the sex of her children by changing the temperature of the nest; too hot or too cold means more girls!

When Alice went to Wonderland, she recited a poem about Nile crocodiles; the poem praised their “shining scales” and “gently smiling jaws”. But what she should have praised was their ability to determine the gender of their children. As is the case with many other reptiles, the Nile crocodile can change the sex of its children simply by changing the temperature at which the eggs are incubated. If the eggs are kept between 89.1°F and 94.1°F, then the babies that hatch are male. But if the eggs stay too cold or too warm, then the babies that hatch are female.

A baby Nile crocodile hatching (Image courtesy Africa Wild Trails)

A baby Nile crocodile hatching
(Image courtesy Africa Wild Trails)

This would normally just be an interesting and somewhat puzzling phenomenon; biologists could (and have) argue for years over why such a mechanism for determining the sex of the offspring is necessary. But the world is currently undergoing something of a heat wave. The past fifteen years have been stuck on “hot” and the next few decades don’t look much better. And what that means is that the Nile crocodiles will have a harder time keeping their eggs in the temperature range needed for male hatchlings. In effect, the number of male Nile crocodiles will serve as a proxy for the temperature.

And Nile crocodiles are far from being the only critters that will change as the climate does. Trees will sprout further up on mountains, and butterflies will migrate earlier in the year. Flowers will bloom earlier or later. And even fish may change their spawning in response to changes in the climate.

Naturally, phenologists (scientists who study the timing of natural events) would love to record all of these changes. But Nature has the phenologists out-numbered eleventy billion to some. And that’s where you come in. If you would like to spend a little time each week observing the flowers in your backyard or the birds in your neighborhood or any other regular natural event, then the folks at the National Phenology Network would like you to become a Nature Observer! Just mark down your observations and add them to the easy-peasy web form and watch as the phenologists use your data!
https://www.usanpn.org/nn/become-observer

September 4 – Turtles all the way down

Today’s factismal: Baby box turtles like to eat insects, slugs, and snails. Adult box turtles like to eat fruits and vegetables.

If you grew up in Oklahoma, Texas, or Louisiana, odds are that you had a box turtle for a pet as a child. And you probably wondered why your little turtle friend would never eat the lettuce that you put out for him. The answer is simple: just like young humans, young box turtles don’t eat their vegetables. Instead, they prefer to munch on insects, slugs, snails, and other turtle junk food. But, as they get older, the box turtle’s diet shifts and they start to eat more plants (probably because the plants can’t run away from them the way that insects do).

A box turtle sits on a rock, contemplating how he got into this predicament (My camera)

A box turtle sits on a rock, contemplating how he got into this predicament
(My camera)

That’s not the only way that box turtles are like people. Box turtles age at about the same rate that people do, too! Most box turtles grow very slowly after they hatch and only reach maturity (read: get ready to date) once they are about ten years old and six inches long. Female box turtles lay one or two clutches of eggs each year, with three to six eggs in each clutch. The adult box turtles then continue to chase plants and each other for the next twenty to forty years; some researchers even report seeing 100 year old box turtles!

But there’s something out there that may keep most box turtles from living that long: people. Many box turtles are taken to sell as pets or food, and others are killed by cars as the turtle crosses the road (to get to the tossed salad, in case you were wondering). As a result, the number of box turtles in the wild is shrinking. How far? We’re not sure. And that’s where you come in! If you spot a box turtle in Texas, then please report it to the Texas Nature Trackers: Box Turtle Survey Project. And then reward yourself with a nice, juicy worm! (Or an ice cream cone. Your choice.)
http://www.tpwd.state.tx.us/huntwild/wild/wildlife_diversity/texas_nature_trackers/box_turtle_survey/