It’s NaCl – sodium chloride! Answer to Freak of the Week #38

Specimens of halite.
Specimens of halite.

Good job readers! Everyone recognized these crystals as salt (sodium chloride – NaCl), seen here in its original form as halite – also sometimes called rock salt. Halite is generally colorless or white but may appear in a variety of colors, depending on the amount and type of impurities. Note the orange-colored specimen in the photo. We mentioned that halite can be identified by its salty taste, however you don’t want to go around tasting unknown minerals! Some minerals that resemble halite can be toxic. Or if it IS a specimen of halite, as you might find in a classroom or museum, it may have been handled by who knows how many people! If geologists need to test for halite by using the taste method, they will lick their finger, rub the mineral, then taste their finger, thereby vastly limiting the amount of material actually ingested.

Halite - backlit to show color.
Halite – backlit to show color.
Halite can be found in areas such as the Great Salt Lake and Searles Lake, California, where it crystalizes out of evaporating brine lakes. It can also be found underground where large salt lakes and ancient seas have evaporated millions of years ago. And halite can be found right here in Ohio! For instance, underneath Cleveland is a huge salt deposit that is currently being mined for rock salt for highways.

Although halite is mainly sodium chloride, table salt is not just halite that is ground up. Most table salt is refined from the original material by first dissolving it in water, then other minerals in the salt are precipitated out, and finally it is re-evaporated. If ingredients such as iodine or anti-caking agents are to be added, it is done during the refining process.

So the next time you’re putting salt on your dinner, just think that you‘re consuming salt that probably was part of a prehistoric sea! We have a nice specimen of halite on exhibit in the mineral section of the Natural History Mall at the Ohio History Center. So come on down and check it out, along with the other amazing minerals on display!

Upcoming workshop on plant collecting, held at Cedar Bog.

A mounted herbarium specimen
A mounted herbarium specimen

Are you interested in learning how to collect and mount plant specimens for scientific or educational purposes, or for personal use!? Then attend the upcoming workshop at Cedar Bog Nature Preserve on “Mounting and Storing Plants” on Saturday, July 11th at 10 AM! Conducted by David Dyer, Curator of Natural History, this two-hour workshop will cover the ethics of plant collecting, methods of pressing and drying specimens, use of archival materials, and different methods of mounting plant specimens. A properly collected, mounted and stored specimen will last for hundreds of years! Over 130 specimens collected by Lewis and Clark on their expedition across North America still survive after over 200 years. The workshop will have a hands-on approach and participants will be able to practice mounting dried plant specimens.

The cost is $10, and for Ohio History Connection members or Cedar Bog Association members it is $5. To register, call 937-484-3744 or email cedarbog@ctcn.net
For more information on Cedar Bog, click here.

Preparing herbarium specimens - photo by Jennifer Cross.
Preparing herbarium specimens – photo by Jennifer Cross.

Beautiful crystals! Freak of the Week #38

Freak of the Week #38
Freak of the Week #38

This Freak of the Week is a mineral, can you identify it!? But it’s not totally fair to ask you what it is by only seeing photos. If you were holding this mineral in your hand you would notice a distinctive feel. Furthermore, it is one of the few minerals that you can actually identify by it’s taste! Any ideas what it might be!? To give you an idea of scale, the larger specimen is about 4 x 3.5 inches.

Closer view of the larger crystal.
Closer view of the larger crystal.

Backlit mineral, to show color.
Backlit mineral, to show color.

Horse teeth! Answer to FoW #37

Horse teeth
Horse teeth

Several of you recognized that these two teeth are from a horse. Horse teeth are very distinctive; note the squareish shape of the chewing (occlusal) surface of the tooth. In side view, this gives the tooth an overall rectangular appearance. These are upper premolars (PM2 & PM3); lower cheekteeth will have a more rectangular occlusal surface. A “tall” tooth like this, with a high crown, is called “hypsodont”. This means that the enamel of the tooth extends down the length of the tooth, well past the gumline. In the side view (below) I drew in the approximate location of the gumline, about one-quarter of the way down from the occlusal surface. This type of tooth is different than a low-crowned tooth, such as in humans, dogs, cats, etc., where the enamel stops at the gumline.

Gumline in high-crowned (hypsodont) horse teeth.
Gumline in high-crowned (hypsodont) horse teeth.

Also you can see how complicated the cusp pattern is in the top photo! There are ridges of enamel running down the length of occlusal surface, and some of the ridges are infolded and run across the tooth surface as well. This is called a lophodont crown pattern, and is found in mammals that are primarily grazers. If you’re eating coarse vegetation such as grasses all day long, you need a tooth with a tough occlusal surface made up of ridges of very hard enamel. Grasses contain a large number of phytoliths, microscopic granules of silica, which are very abrasive and can wear down a tooth pretty quickly. So a hypsoodont tooth is an adaptation to a grazing diet because of the phytoliths in ….

WHOA, HOLD EVERYTHING! WE INTERUPT THIS BLOG FOR A SCIENCE UPDATE!!!
Recent research has shown that the adaptation of a high-crowned tooth probably happened as a result of the large amount of grit ingested from the soil when grazing, rather than from the grass itself! Paleontologists looked at when the extensive grasslands originated in the Great Plains of North America, and discovered that high-crowned teeth evolved in different mammal groups either millions of years before or after the grasslands developed. So the teeth likely didn’t evolve in response to the abrasive grass but from another cause, the grit itself! Think of how dirty your hands get when weeding your garden or lawn, and imagine you’re eating that stuff! There’s a lot of grit and minerals in the soil that would wear down even the hardest material in an animal’s body: tooth enamel.

So back to our two teeth; how do we know that these aren’t from a cow, cows are grazers and have high-crowned dentition!? Well, if we compare the crown pattern of cattle teeth and horse teeth we can see the difference (below). Cattle have a selenodont crown pattern which means that the crown is composed of a series of “half moon” shapes, called selenes, which run the length of each tooth. If you know your Greek mythology (which I don’t!), Selene is the goddess of the moon.

Upper toothrow of domestic cattle
Upper toothrow of domestic cattle

Upper toothrow of a horse
Upper toothrow of a horse

OK, we’ve established that they are horse teeth but Bob brought up a good point: how old are they!? We know that horses lived in Ohio during the Ice Age, and became extinct in North America after the end of the Pleistocene. They were then introduced back into North America by Europeans at about 1500 A.D. and have been here ever since. Because the modern horse and the Pleistocene horse are so similar morphologically, they are very difficult to separate – especially by just a tooth or two. Documented Pleistocene horse remains from Ohio are pretty rare, so most bones and teeth discovered are probably from the modern horse. We would have to find horse bones in Pleistocene deposits to prove that they are indeed from the Ice Age, and we’d have to be sure that it’s not a modern horse that was simply interred into Pleistocene sediments! So the next time you’re out horsin’ around, keep your eye out for these distinctive looking teeth!

Big teeth! Freak of the Week #37

What are these teeth from? Freak of the Week #37
What are these teeth from? Freak of the Week #37

This is the time of the year that people are out working in their gardens or digging in their fields. Sometimes bones or even individual teeth are found, and are brought to the museum for identification. If you came across teeth like these, would you know what they are from!? These are pretty big teeth too; the scale in the photos will show you that the teeth are over an inch wide and about 3 inches long. Put your answer in the Reply box below.

Side view of the teeth.
Side view of the teeth.

You “knee-d” to know this! Answer to Freak of the Week #36

Elk, with joints labelled
Elk, with joints labelled

Bison, with joints labelled
Bison, with joints labelled

Great Blue Heron - note that the femur is concealed under the wing and feathers but I marked its location in white.
Great Blue Heron – note that the femur is concealed under the wing and feathers but I marked its location in white.

I couldn’t trick our astute readers with this question! You are all correct, those are indeed ankles and the knees do actually bend forward. Sometimes people get confused because the upper limb bone of the hind and forelimb, the femur and humerus respectively, sometimes gets “lost” in the mass of the body. That, combined with the fact that many animals have extended the length of their feet and now walk on either their toes or on the ends of their hoofs, makes it appear that the ankle is actually the knee!

Both the elk and bison are considered “unguligrade” meaning that they walk on their hooves. The keratin hooves encase the last toe bone, so basically they are walking on their tip-toes! This means that most of the foot is actually off the ground and the heel bone (calcaneus) projects to the back of the animal, and can look like a “backward knee”! Sometimes this is easier to see on the skeleton:
Feet of mammals

Why did some animals evolve such a system? For speed! The elongated leg and fused bones of the foot provides for greater speed in a forward direction. Notice how many of the prey species are unguligrade, such as deer, elk, moose, pronghorn, bison, etc. while many of the carnivores (canids, felids, etc.) are digitigrade – meaning that they run on their toes and not just on the last digit.

“Why do deer knees bend backwards!?” Freak of the Week #36

Elk
Elk
Bison
Bison

Here is a little bit different Freak of the Week for you! It’s a question that I’ve been asked several times, so I thought I’d put it out there for you to ponder: “Why do deer knees bend backwards?” It’s not just deer, but the question can be asked of elk (which is really just a large species of deer), bison, cattle, horse, or any other large ungulate. In fact, this apples to most birds too! See the photo below of the Great Blue Heron. How would you answer this question!?

Great Blue Heron - © Frank Schulenburg / CC-BY-SA-3.0
Great Blue Heron – © Frank Schulenburg / CC-BY-SA-3.0

Return of the Snakes

Have you been to Serpent Mound yet? If you needed an excuse to visit this iconic OHC site, I’m here to give you one: The Return of the Snakes, a family-friendly event run by our site parter, the Arc of Appalachia Preserve System on June 27 from 10-4.

The largest collection of Ohio’s native reptiles and amphibians ever gathered in our state will be displayed at Serpent Mound, while teaching about their natural history, ecology, and conservation challenges.

Special Events

  • Ohio’s native reptiles and amphibians on live display (don’t worry – both you and the animals will be completely safe).
  • For Adults: Presentations every hour by Ohio’s finest researchers & field naturalists – Ohio’s endangered reptile and amphibian species, identification, and natural history.
  • For Kids: Toad feeding, turtle pool, games, stories, and crafts. Touch a real live snake! Jr. Herpetologist hike for budding naturalists (please pre-register on the website).

Event Schedule: http://arcofappalachia.org/events/snakes-schedule.html.

Directions to Serpent Mound: http://arcofappalachia.org/visit/serpent-mound-directions.html.

 

We hope to see you there!

 

 

Leave Wildlife in the Wild!

Deer fawn - photo by ForestWander Nature Photography.
Deer fawn – photo by ForestWander Nature Photography.
It’s springtime, which means it’s also time for the annual reminder from our friends at the Division of Wildlife – Ohio Dept. of Natural Resources: enjoy wildlife from a distance and leave young animals in the wild! At this time of year, we might see baby squirrels on the ground or a deer fawn hiding alone in the underbrush. It’s tempting to intervene but wildlife officials remind us that:
“Many adult wild animals will leave their young offspring alone while they forage for   food, or to divert the attention of potential predators away from the more vulnerable young. When young animals are discovered with no adults in sight, the adult is often nearby waiting for people to leave the area before they retrieve their young.”

Baby_birds_in_a_nest_in_a_tree_in_NJThey also dispel the myth that if humans handle a young animal then the parents will no longer take care of it. If humans disturb a nest, the young and the nest material should be replaced as close as possible to the original location. But generally “only licensed wildlife rehabilitators, working under special permits issued by the ODNR Division of Wildlife, may possess and care for native wild animals”.

You can read the full article here.

Bones of a cool Ice Age animal! Answer to FoW #35.

Cervical (neck) vertebrae of an Ice Age muskox.
Cervical (neck) vertebrae of an Ice Age muskox.

We had some good guesses from our readers as to what animal these bones are from, and we had to consider such species in identifying these vertebrae. You can see in the photo below that the cervical (neck) vertebrae of the larger, more common species from Ohio do not match the unknown bones! Bison, which are not pictured, are very similar in the post-cranial skeleton to cattle and can also be eliminated from the list of suspects. The most noticeable difference is how wide the body (centrum) of the vertebrae are, much wider than any of the species below.

So we’re left with a large ungulate, with a relatively short, wide neck. Hmmmm!? The only animal that could fit this bill is a muskox! Could it be!? There have been only a handful of records of muskoxen from Ohio, and this would be a nice find. So I sent the photos to the well-known Pleistocene vertebrate paleontologist Dr. Greg McDonald of the National Park Service; he fired back an email: “They are indeed muskox!”.

Cervical vertebrae  of horse, cattle, and prehistoric elk.
Cervical vertebrae of horse, cattle, and prehistoric elk.

Now the question is, what species are they from? There were two types of muskox in Ohio during the Pleistocene, the modern Muskox (Ovibos moschatus) which now lives in the Arctic, and the Woodland Muskox (Bootherium bombifrons) which became extinct at the end of the Ice Age. The Woodland Muskox was taller and thinner than the modern Muskox, and was the most common muskox in the midwest during the Pleistocene. To properly identify these vertebrae, we’ll need to see the bones in person and maybe take them to another museum to compare to known specimens of muskox. We are hoping that the bones will be donated soon to the Ohio History Connection. Then we can not only determine what species they are, but also have the specimens available for research, teaching, and exhibit. Which species do you think they will be from!? We’ll give the answer as soon as we know!

Modern Muskox
Modern Muskox
Skull of the extinct muskox Bootherium.
Skull of the extinct muskox Bootherium.