A local daily newspaper* recently published an account the discovery of giant fossil clams.  These measured four feet across, twice the size of any living species, and found in Utah for the first time.  Similar fossils are said to have been found in Colorado and Kansas, but this is the first time such prehistoric invertebrates have been found this far west.  L. Logan and K. Carpenter of the Utah State University-Eastern’s Prehistoric Museum* found a number of fossils in the Book Cliffs, near the Green River.  A number of clam remnants encountered were eroded so badly they could not be collected, but finally one was found with little erosion damage.  This specimen was collected and taken to the Museum.  The giant clam fossils were found in mancos shale, named for the Mancos Sea that is thought to have cut through North America from the Arctic Ocean to the Gulf of Mexico in the far distant past.  The foto above shows typical extant East coast clams.

A little bit about fossils.  Fossils are the remains, impressions or traces of the bodies of organisms which have been preserved in rocks from previous geological ages.**  Fossils that retain perfect or only slightly modified forms of plant and animals are rare.  Over many years, plants and animals have had their outer skeletal parts dissolved by chemical processes, then replaced by minerals such as silica, calcite, etc.  There is almost always the loss or dissolution of the original structure.  Again, various minerals replace dissolved skeletal parts so that none of that original part remains.  However, sometimes fossils have retained the original patterns perfectly both externally and internally (exoskeleton, endoskeleton); these are the most desired and sought after, but—also the most rare and difficult to find.

Indeed, there are some few examples of actual fossil skeletal materials remaining after thousands of years.  These include skeletal parts found frozen within ice in Siberia and the skeletons of higher animals preserved in asphalt in Rancho la Brea in California.

Of course, the likelihood of fossilization for any given plant or animals is very small.  After death, as these are most often eaten or destroyed or simply decay away on the surface.  Obviously hard body components such as teeth, bones, shells, and wood are the most likely candidates for fossilization.  Vertebrate paleontologists have created new species of vertebrate animals based on fossil teeth (dentition) found, often in caves.  Certain conditions must be met, however, for fossils to form.  First, the body or plant must be covered fairly rapidly after death—most commonly with sediment.  Sediments offer protection from mechanical damage, normal biological decomposition, or the actions of water or atmospheric events.  Thus marine or aquatic organisms are much more likely to become fossils than land dwelling (terrestrial) animals or plants.  Additional important requirements for fossilization are extreme pressures generated by multiple layers of sediment and detritus above and…. time.   Extreme pressure over many thousands, even hundreds of thousands of years, often produce recognizable animal and plant species.

Now some more about clams in general.  Clams or “mussels” are often called “bivalves.”  The “bi” refers to two, and the “Valve” refers to the shell; or in other words, two shells.  The innermost layer of the shell is called the “mother of pearl.”  It consists of alternating layers of limey and horny material.  This produces an attractive iridescence which diffracts light and which in the past, has made clam shells much sought after to make buttons and jewelry.

Clams are, of course, marine or aquatic organisms.  They lived in the sandy bottom of bodies of water and can be dug up from sandy seaside beaches.  Clams and their kin may be found throughout the earth from the deepest marine seas to shallow fresh water rivers.  Clams have no head.  They have a mass of flesh in the ventral (lower) part of their bodies called a foot, which, when the shells open can be extended and provides slow movement as it contracts and expands.  The two “mantles” are fleshy lobes inside the shell that secrete the bivalve shell and the “hinge.”  The hinge opens to allow food-bearing water to circulate within the mantle.  Food is captured and enters a crude digestive system.  When enemies threaten, the clam simply closes up tight to protect its inner self.  A single large muscle is responsible for governing opening or closing of the bivalves.  This muscle is the sought after morsel that humans find so delectable in making clam chowder.

My own experience with clams came as a result of an invertebrate biology class I took while a student at the University of Oklahoma’s Lake Texoma Biological Station with four classmates.  Dr Barry Valentine (Ohio State University) taught the class and we traveled throughout southern Oklahoma waterways in pursuit of fresh water clams of which there are a number of species with varying architecture.  Most of the specimens we collected were from animals already expired.  However, at the end of the class, besides the master collection which yielded new distribution information of several species, we each had a collection of attractive and varied fresh water clams.  Mine eventually went to Weber State University.  Overall, It was a most memorable biological collecting experience!

*Liesk, J.  2013 (4 Feb).  Giant Clam Fossils Unearthed.  Deseret News, SLC, UT.

*Prokop, R. and V. Krb.  1995.  Fossils.  Magna Books, Leicester, England.

***Utah State University – College of Eastern Utah.  2013. News, Big Find-Giant Clams. website:  eastern.usu.edu

Of the 800,000 total animal species (or kinds) in the world, how many have you seen personally?  Have you kept track of those you have seen (probably not as these include insects and other invertebrates)?  Have you ever heard of an animal checklist?

Perhaps you are familiar with a group of devoted animal adherents called “birders.”    Birders or “bird watchers” are well known for constantly looking for (and often keeping  records) birds they see and can identify.  Many use “checklists.”  A checklist is a printed listing of all birds known from certain areas, such as a state or national park, state, or geographical area, perhaps even an entire country or continent.  There are blanks in each checklist beside each bird’s name to record specifics about sightings (date, location, etc.).  There are around 8,600 bird species worldwide, so there are almost always birds to see and record wherever you live.

Bird watchers may visit any place where a bird is likely to be seen, including their own backyard feeding station, neighboring orchards or even nearby public parks.  Some visit specific habitats, such as marshes to look for wetland-adapted shore birds.  When seen, definite sightings are recorded on checklists as they are identified.  Novices, even veterans, carry field guides containing avian color photos or pictures or other information so identification can be certain.  Many birders maintain lifelong checklists.  Being a bird watcher includes having a curiosity/love for birds, a pair of binoculars and willingness/ability to make the effort to get out-of doors, perhaps travel, and identify feathered fauna in a variety of weather conditions.  At least once a year at Christmastime, birders organize and participate in an end-of-the-year census or bird count to assess numbers and presence of species of local and migratory birds.

Not so common are other animal checklists.  My favorite animals are mammals, so I will discuss them here as examples.  There are only about 60 percent as many species of mammals, 5,000, as compared to birds; only amphibians have fewer species than mammals, about 1,500.

Most mammals (except bats) are confined to the earth’s surface or subsurface, and their movements are much less rapid and less likely to be seen than birds.  Hence, the process of building an extensive checklist of identified mammals is more laborious than birding–though equally rewarding.  These watchers are folks who similarly look for and record sightings and experiences with mammals.  As you know, mammals are warm blooded animals with hair, females with milk glands giving birth to living young (we humans are classified as mammals).  Common animals classified as mammals include aquatic mammals (such as whales, dolphins, seals, manatees), aerial mammals (bats) and terrestrial four-footed mammals (as elephants, bears, squirrels, mice, kangaroos).  These are widely distributed throughout the earth.  There have been extensive mammal extinctions in earlier periods of the earth’s history and even today some kinds of mammal populations are so low they are considered threatened and/or endangered.

Animals, including mammals, can be detrimental to man.  Some destroy grain, cereal and other crops, some are vectors harboring disease organisms, and some are known to physically attack humans.  However, many kinds of mammals have been useful to man throughout the ages.  Even today, they serve as beasts of burden, transportation, medical research subjects, and subjects of aesthetic enjoyment.  Mammals continue to be useful for food, fur and body parts, as pets, as quarry in sport hunting and even for subsistance survival in some parts of our planet.

Mammal sightings may occur in zoos, animal parks or actually out in the wild—in national forests and wilderness areas, in oceans and rivers; in fact, in almost any habitat imaginable.  A favorite activity of some families is to visit national and state parks, water parks, shorelands, ride ATV trails, etc., all the while keeping a sharp eye out for wild mammals.  Newly identified mammals are readily added to personal or family checklists  which continue to grow and grow.

There are a number of sources of checklists.  Many parks, national and local animal interest groups, nature trails, etc., maintain checklists of local animals.  Look on the internet under “Checklists” to find one you might be interested in.  One such mammal checklist is found at: nsrl.ttu.edu/publications/opapers/ops/op229.pdf.  This checklist lists all mammal species and subspecies north of Mexico (in the U.S. and Canada) giving common, scientific and subspecies names.

Let’s briefly talk about animal names.  As humans, each individual has unique names, usually two or three names that become ours alone, as Alex Brian Smith.  In the past, some human cultures have used only a single name, leading to great confusion among descendants trying to find their ancestors.  Among animals of similar kinds (or species; not as each individual as in humans), each has a unique name or “handle” called a scientific name.  A scientific name is a universally recognized two or three word name given to specific kinds of animals.  No two different kinds of animals have the exact same scientific name, even though some species are quite similar.  The first part of a scientific name is the Genus, followed by the Species name.  For example, a red fox’s scientific name is Vulpes fulva.  As shown here, when written out, scientific names are underlined or printed in italics.  Often, scientific names reflect a quality of the animal in Latin word roots:  “fulva” means red.  Along with the scientific name, most animals also have a common name, as “red fox” above.  Common names are easier to use and remember.  However, a difficulty is that several very distinct and different kinds of animals may all have the same common name (See Wildlife2Day. com website article, “When is a Gopher Really a Gopher?).

Kinds of animals living close to one another interbreed and produce fertile offspring.  These are considered by scientists to be the same species.  Over time, members of the same species living apart and under different environmental or other stresses may eventually adapt body differences, such as differing hair coloration.  These are then given “subspecies” names, the third name following the genus then species name to distinguish them from each other–but they can still crossbreed and reproduce fertile young.  Changes resulting from environmental factors (flooding, catastrophic storms, coal strip mining, production of dense smoke by new factories), human activity (turning former habitat into housing subdivisions, roads, airports, etc.), or other factors often cause a permanent separation of similar animal populations.  Over longer periods of time, even thousands of years, this separation or isolation (and possibly) other factors may result in formerly adjacent, similar species to no longer have the ability to crossbreed and produce fertile young.  Hence–a new species!

One-Eyed Sentinel of Aberdeen—A Saga Set in the 1970’s

Perched on a railing four stories up, the two Great Horned Owls appeared from the street below as tiny, feathered statuettes, though in reality they approached two feet in height with a wingspan of up to five feet. For almost four years, with the exception of about a month each summer, this pair of owls has kept their vigil in the Aberdeen, South Dakota, Brown County Courthouse tower, only a few yards away from the great multifaceted clocks. Chimes boom out on the hour, but these sounds so foreign to nature appear to have had little effect on these feared birds of prey.

The female is blind in her opaque yellow right eye for some unknown cause. She has laid a total of nine eggs in the past three seasons in early spring. In 1976, she initially laid two white eggs which froze–perhaps due to wind chill temperatures which have often been well above minus 50 degrees Fahrenheit in the wintertime, though somewhat warmer at time of early spring egg production. Instinctively striving for a successful mating, she laid an additional three eggs which were subsequently incubated about 30 days before hatching three young. Due to unknown factor(s), all three died shortly afterwards and their remains vanished.

The next year, the female laid two eggs that hatched in a month. As the young matured, the white feathers of the two young were easily visible from the ground below. Twice, these two partially fell, partially glided to the earth below but were soon returned to the tower by concerned county workers. The young disappeared a few days later after learning to fly and have not been seen again.

A sizeable population of pigeons have made the courthouse tower their home for many years. Some years previous, tons of accumulated pigeon droppings and debris crashed down into the inner courthouse corridor far below causing structural damage to the building. So, as a result, prior to the owl’s presence, Brown County officials regularly paid up to $200 per month for cleaning and removal of pigeon droppings. In fact, after the owl pair first moved into the tower, country officials were so desirous of insuring their permanent residence, that they provided raw flesh as food. The birds not only refused to eat it, but they subsequently left the tower briefly. Following residential occupation by the two Great Horned Owls, the pigeon cleanup costs were cut by 90 per cent.

Pigeons nesting further up in the courthouse dome of the bell tower offered a convenient and ready source of food. The owls, with their sharp, grasping claws and razor-like tearing bills are uniquely equipped to capture and kill unsuspecting prey. The term “Tiger of the Air” has been aptly applied to this courageous, powerful and bloodthirsty predator. Several times in the early pre-dawn hours, one of the owls was observed dive-bombing a pigeon in flight. The immediate result was a great flurry of feathers resulting in the hapless victim, grasped by vice-like claws in midair, being carried back to the tower roost for a tasty meal.

The author remembers a wintertime personal experience with a Great Horned Owl only a few miles away from the Courthouse. I had set a number of traps with the intent of capturing red foxes for their pelts which were bringing $60 at the time. Following standard fox trapping protocol, I had carefully de-scented traps and carefully set two of them near each other in a field not far from a small pond. The double springed traps consisted of a spring on one side attached to jaws surrounding a trigger in the middle with an attached spring on the other side. When checking the traps a day or so later, I found a dead jackrabbit in one of the traps and a very much alive Great Horned Owl in the other. I had no quarrel with the owl and set about to release it as harmlessly and efficiently as possible. However, due to the nature of the double springed traps which required simultaneous compression of each on each side, I had a problem. For, as I sought to release the spring with my hands on each side of the trap, the owl would attack me with wings and bill–so I had to use one hand and arm to shield myself from the owl’s attacks, which prevented compression of both springs of the trap at the same time with each of my hands. After a few futile efforts to open the trap with one hand, I finally was able to use one knee to compress a spring on one side at the same time as I pressed the other with one hand, all the while fending off the owl’s attacks with my free arm and hand. This done, the jaws still refused to open to release the bird, so it took a few more tries of jarring the trap back and forth before the jaws finally opened and released the big bird–which wasted no time in flying off. The scenario that originally resulted in the two trapped animals side by side probably began when the rabbit stepped on the trigger and while flailing around trying to escape, the Great Horned Owl, cruising above for food, spied the bunny and deemed it an easy meal. However, in alighting and seeking to secure it, the owl had itself become caught in the other trap. Subsequently, the owl had killed the rabbit, but remained trapped itself. It is possible this was one of the Tower Great Horned Owls, but there is no proof.

Postscript:
Owls are nocturnal; that is, they are most active during the night time. Their large disc-like eyes are capable of detecting the slightest movement in limited night light. Their wings are feathered especially to facilitate silent flight—-the element of surprise to unsuspecting prey. Their diet is diverse, mainly dependent upon kinds and numbers of prey animals available. A variety of nocturnal (sometimes diurnal) animals including skunks and jackrabbits are common owl cuisine; however, only captured living creatures are eaten, never prey already dead such as those dined upon by eagles and vultures and other avian scavengers. Great Horned Owls, with peculiar feathery tufts at the sides of their heads resembling horns from a distance, are among the largest of all owls and are said by some naturalists to be the most savage birds of prey. They are common throughout North America, most generally living in forested and brushy areas, canyons, cliffs and deserts. A peculiarity of owls is that their eggs (usually two) are laid at intervals so that there may be an older maturing fledgling hatched in advance of other unhatched egg(s) in the same nest.

Early one morning, Phineas Pika (a small tailess cousin to rabbits also called conies or rockrabbits) sat quietly sunning himself. He was on his favorite lookout rock outside his den in a rocky slope situated high in the mountains of the Gray’s River country of Western Wyoming. The year was 1840 and it was already late May. The few remaining drifts of unmelted snow lay in stark contrast to the newly awakened landscape of a few bright yellow dandelion flowers, dark green evergreens, quaking aspens with their brilliant white bark, and the bright blue sky. Close by, Gray’s River, just a trickle a few miles upstream, had now grown to a rather formidable stream, almost large enough to be a river.

Phineas lived with other pikas in his den hollowed out underneath a slope littered with large, craggy rocks. His winter coat of gray-brown fur, now slightly ragged and faded after a long cold winter, would soon molt away and be replaced by new growth. His fur had served him well during the long winter when the temperatures had plummeted to 40 degrees below zero. His winter’s food supply, carefully harvested dried plants, appearing somewhat as miniature farmer’s haystacks, was depleted. Phineas had worked especially hard last summer in order to store up enough food for the long winter, even much more than his family really needed. This was fortunate indeed as an unforeseen event had occurred the past December that could have caused the family starvation. Thinking back, Phineas remembered and rehearsed to himself the rather remarkable events as he was able to reconstruct them:

Late one December day when all of the small mountain animals were curled up warmly and securely in their dens, a huge blizzard with strong winds descended upon the high country following several days of intense snowstorms. The wind whistled through the nearby pines and purred through the rocks. The falling snow was sculpted into fantastically appearing drifts as though shaped by unseen human hands. The nearby river, almost covered by ice, was piling higher and higher with snow, rendering the flowing stream of water beneath invisible. Phineas had no worries, as his supply of food, piles of dried grasses, were secured nearby under a blanket of snow, or so he thought.

On the far side of the flat below the rock slide, the unexpectedly ferocious storm had caught a trapper unawares. Big Jim, as he was known by his fellow mountain men, had been at the end of his trap line checking beaver traps when the snow began falling two days ago. He and his faithful mount, Jupiter, had already spent two incomprehensibly cold nights with only little shelter. His faculties, already strained and chilled, had led him to leave his crudely constructed shelter in order to begin the long trek to his cabin far down the canyon. Then the storm had set in, with the wind churning the snow into a blinding whiteout. The strips of jerky he had taken along for food were long since gone. Jupiter had not eaten for three days. Horse and rider were now at the end point of their physical strength. Bucking huge snowdrifts had consumed all of their energy reserves and they wandered aimlessly down the canyon, not being able to even see or follow the trail. Unbeknowns to Phineas, the two had come to a frightening stop directly over his den. Both were devoid of energy and were bitterly cold. Almost certain death lay awaiting. Fearing the inevitable fate of freezing, as every mountain man was accustomed to face, Big Jim vaguely thought about crawling towards the grove of aspens on the far side of the rock slide, but utter exhaustion finally overcame both man and beast.

The rosy warmth of mortal cold began to feel tantalizing irrestible. With the instinct of the mountains, Big Jim semiconsciously began to dig in the snow. His mittoned hands pawed into a “new“ kind of snow—it was in fact, Phineas’ winter store of dried plants! A slight whinney of recognition of food elicited from Jupiter’s throat. Half-startled, Big Jim vaguely recognized his “find.” Burrowing as far under the pile of dry grasses as he could, Big Jim slept—while a famished Jupiter feasted.

Sometime later in the day, Big Jim, glorying his his newly found “warmth” was annoyed by the constant tugging at his clothing. He clumsily swung a half frozen mitton to be rid of the bothersome pest–old Jupiter–who was rudely interrupting his comfortable reverie. Persistent tugging, however, finally paid off as Big Jim grudgingly awoke. He foggily regained his senses with great effort, gradually remembering their precarious situation and grateful the wind had ceased.

Clumsily and Wearily he grabbed hold of a saddle stirrup and urged Jupiter towards the dense stand of pines and quaking aspens a short distance away. Entering into the midst of the trees where there was less snow, Jim pulled off some dead aspen bark from a fallen tree. He shredded the soft inner bark as finely as he could into a small, dry ball and then clumsily fumbled for his flint and steel. After a dozen or so tries, he was finally able to protect a small spark and nurse it gradually into a full blown fire. Finally warm, he constructed a crude lean-to for protection. The continued warmth of the fire was life-saving. He made several trips to Phineas’ nearby hay pile to feed Jupiter. He himself was able to chew on chunks of some of the remaining fat and flesh still clinging to several of his beaver hides. Their nearly starved bodies gradually regained some of their strength. When he felt stronger a day or so later, Big Jim and Jupiter proceeded on down the canyon to the one room cabin and outlying shed each called home.

Phineas and his family were a bit hard pressed the remainder of the winter to find sufficient food to eat. They had hidden several smaller piles of dry plants
a short distance away and concealed under the heavy snow. Fortunately for the pika family, Old Man Winter left the high country unseasonably early, or they might not have survived. Now, though, wild plants were again beginning to push through the ground, offering a new and welcome supply of nourishment.

Painfully vivid and uncomfortable memories seem to diminish as time moves on—and Phineas pika could never fully know of the gratitude of two of Star Valley’s original “mountaineers.”

Postscript – Have You Ever Personally seen a Pika?
The pika, rock rabbit or cony, Ochotoma princeps, live in colonies and inhabit rocky talus slopes and large boulder-strewn hillsides of western North American, Canadian and Alaskan mountains. Pikas have underparts of creamy white, upper parts of gray/brown. They live at altitudes normally in excess of 7,000 feet, although some have been found at sea level. They have excellent hearing and vision and climb from rock to rock with ease.
Breeding season is in May and early June, with 2 to 6 young per litter. Young are born blind and hairless after a gestation period of about 30 days and reach adult size in 40 to 50 days. At one year of age, females can produce young and sometimes even two litters per year may be born. Longevity is about two to three years. Pikas have a home range of about 30 m in diameter. They are quite vocal, emitting several kinds of calls, especially a steady series of “kie” sounds. Hay gathering usually begins in late June by cutting and dragging nearby local plants to the den site. Each pika makes several haypiles within its home range.