The Pleistocene Penis

December 17, 2014

Organisms with separate male and female sexes evolved from hermaphroditic ancestors.  Hermaphroditic species are still common.  Many species of plants and some species of animals are able to self-fertilize because they are both male and female.  One would think the evolution of an hermaphroditic organism to a species with separate male and female sexes happened so long ago that it would be impossible for biologists to study.  But, surprisingly, this is not true.  There are over 100 species of plants in the evolutionary process of transitioning between hermaphroditism to a state of separate sexes.  The most familiar species in this transitional state is the wild strawberry, Fragaria virginiana.

Biologists believe the evolution of separate sexes was the result of a beneficial mutation.  Organisms that have separate sexes have increased genetic variation, thus improving the chances the species will survive.  Hermaphrodites suffer higher rates of inbred defects and eventually are eliminated from transitioning populations by the hybrid vigor of male x female combinations.  In stressful environments organisms with separate male and female sexes can allocate resources to seed or pollen, not both–another advantage over the hermaphrodite.

Plants rely on wind and insect pollination.  Males and females of many primitive aquatic animals release sperm and egg in each other’s vicinity, relying on water flow to aid fertilization.  But the evolution of a structure to directly deliver a male’s sperm inside a female’s body was a great advance.  This structure is known as a penis.  The oldest known penis in the fossil record belonged to an extinct species of shrimp (Colymbosathon ecplecticas) that lived 425 million years ago. 

Mammoths and mastodons had the largest penises of any land mammal during the Pleistocene and theirs was comparable in size to those of modern day elephants.

i-2325d7f6567e1a7459f965b85b2d82cd-Elephant-penis.jpg

This bull elephant is in the mood to mate.  Note the large penis.  Mammoths and mastodons had the largest penises of any Pleistocene land mammal.

Homo sapiens has the largest penis of any primate.  There’s no evidence Pleistocene humans ever practiced the bizarre and barbaric practice of genital mutilation known as circumcision.  Circumcisions originated in Egypt about 4400 years ago. Religious fanatics in the ancient Egyptian culture rejected the concept of sexual pleasure.  Circumcision spread throughout the Middle East and Africa and was always popular among religious nuts who thought sexual pleasure was bad.  According to the bible (an unreliable source), the early Jews practiced circumcision, but Moses outlawed the practice.  Joshua brought circumcision back because he wanted his men to focus on smiting gentiles rather than sexual pleasure.  Jews have continued this idiotic tradition ever since.  Circumcision became popular in the United States after the Civil War when once again religious nuts were trying to stop boys from masturbating.   It didn’t work–98% of circumcized males admit to masturbating.  Greedy physicians made up falsehoods, supporting the pro-circumcision crusade, so they could make money on a common but unnecessary procedure.  Even today, most American males suffer genital mutilation shortly after birth, though, thankfully, rates are declining.

About a decade ago, the American Academy of Pediatricians admitted there was no medical reason for male circumcisions.  However, in 2012 religious nuts pressured the AAP to restate their position.  The AAP now states, “the health benefits of circumcision outweigh the risks but the existing scientific evidence is not sufficient to warrant universal circumcision…the final decision should be left to parents to make in context of their religious, ethical, or cultural beliefs.”  So in other words, the AAP is saying it’s ok to torture a baby, if their parent’s religion tells them they are supposed to.  The words cowardly and callous come to mind.

The CDC recently released a report supporting the practice of circumcision because in Africa circumcized men are less likely to spread HIV than uncircumcized men.  Well, first of all, the CDC represents America not Africa.  Second, this reasoning is incredibly illogical.  The spread of HIV could be be completely eliminated if every man had their entire penis cut off, just like broken legs could be prevented with universal leg amputations.  Or less dramatic measures could be taken.  Men could use condoms or engage in sex with less dodgy partners.

There is no medical reason for male circumcision.  There is no significant statistical difference in rates of penile cancer or urinary tract infections between circumcized and uncircumcized men as some have falsely claimed.  There is no moral justication for torturing babies, and I think it is sickening how so many parents are willing to approve of such a stupid, barbaric, religious tradition.  The practice of circumcision, both male and female, should be outlawed.

uncircumcised vs circumcised adult penis

Comparison between a normal penis and the more common (in the U.S.) mutilated penis.

I’m glad I can’t remember my circumcision.  Most American males are strapped down when they are babies and have 12 inches of skin cut off from the most sensitive area of their body…all in the name of religion and tradition.  WHAT AN OUTRAGE!  Are people this insensistive, gullible, and stupid that they would subject their children to torture, just because some stupid rabbi or greedy doctor says they should?

The removal of the foreskin slices off the 5 most sensitive areas of the penis.  Circumcized men are 4.5 times more likely to use erectile dysfunction drugs than uncircumcized men.  These men probably wouldn’t need such medication, if their penises had not been mutilated with the approval of their brainwashed parents.

Reference:

Ashman, T.

“The Evolution of Separate Sexes: A Focus on the Ecological Context”

In chapter 11 of The Ecology and Evolution of Flowers edited by Lawrence Hader and Spencer Barrett

Oxford University Press 2007

Giant Ground Sloths Probably Scavenged Meat

December 12, 2014

Caves located in arid climates preserve ground sloth dung that is tens of thousands of years old.  The shasta ground sloth (Nothrotheriops shastensis) ranged throughout the American southwest during the late Pleistocene and left telltale evidence of its diet in several of these caverns including Rampart Cave, Arizona; Shelter Cave, New Mexico; and Gympsum Cave, Nevada.  From the macrofossils and DNA evidence in this dung we know this species ate a wide variety of plants–pine, mulberry, mustards, agave, yucca, grass, mint, globe mallow, saltbush, Mormon tea, grape, water leaf, creosote bush, hop sage, sagebrush, and willow.  There is no evidence from these coprolites that ground sloths ate meat.  Nevertheless, some scientists hypothesize ground sloths did scavenge meat .   Although ground sloths were too slow to actively hunt most prey, they could have taken advantage of available carrion, and perhaps even usurped the kills of predators.  Ground sloths were powerful beasts with long claws capable of severely injuring a carnivore contesting ownership of a carcass.  Some scientists have even suggested ground sloths could have actively turned over glyptodonts to attack their vulnerable underbelly.

The lack of meat in known sloth coprolites doesn’t preclude the possibility they did on occasion eat animal protein.  Over 99% of white-tail deer feces will show no evidence of flesh-eating.  Yet, we know they do sometimes scavenge meat and even prey on nestling birds and eggs (See: http://markgelbart.wordpress.com/2012/05/11/unexpected-items-in-the-diet-of-the-white-tail-deer/)  Without evidence the hypothesis that ground sloths ate meat is mere speculation.  However, evidence from 1 specimen supports this hypothesis.

 

 

 

 

 

 

 

Artist’s rendition of a Megatherium, a large ground sloth that formerly lived in South America.  The deer in the foreground is a pampas deer (Ozotoceros bezoarticus)), still extant but very rare.

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Photo of a rib interpeted to have been gnawed on by a Megatherium.  From the below referenced book.

A fragmentary rib in the collection of a museum in Uruguay has gnaw marks on it that match the teeth of Megatherium americana, a large ground sloth.  The rib is from either another ground sloth or a mastodon.  (Scientists can’t differentiate among these 2 species from just this part of the anatomy.)  It has 7 shallow marks.  Weathering marks exist over the tooth marks, eliminating the possibility that natural abrasions caused the scratches.  The marks are too dull to have been the result of human cutting.  The marks don’t match those of rodents or carnivores.  However, they exactly match the “transversely bilophodont” teeth of a megatherium.  The spacing of the tooth marks also match the distance between the bottom teeth of a megatherium.  The scientist who examined the marks believes the sloth held the bone upside down and gnawed on it with its bottom teeth.

If sloths ate carrion, I’m sure they would have also eaten ground-nesting bird nestlings and eggs as well.  They likely snacked on insects.  Ground sloths are related to armadilloes and anteaters.  Armadilloes eat carrion, small mammals, eggs, and insects.  Ground sloths probably retained the ability to digest animal protein from their shared ancestry with armadilloes. The evolutionary ancestor of both lines was likely omnivorous.  There’s no reason to assume ground sloths could not have taken advantage of an easy source of protein, though their diet was primarily vegetarian.  This feeding strategy would not be unlike those of bears, hogs, and apes.

Reference:

Farina, Richard; Sergio Vizcaino, and Gerry Del Iuliis

Megafauna: Giant Beasts of Pleistocene South America

Indiana University Press 2013

Poinar, Henrick; et. al.

“Molecular Coproscopy: Dung and Diet of the Extinct Ground Sloth, Nothrotheriops shastensis”

Science 281 (5375) 1998

 

The Antelope Jack Rabbit (Lepus alleni) Lived in Southeastern North America During the Pleistocene

December 9, 2014

Today, the antelope jack rabbit is restricted to desert grassland habitat in western Mexico and southern Arizona, but during the Pleistocene it occurred as far east as Florida.  Fossils of this species have been found at 2 sites in Florida, dating to the middle Pleistocene.  Over 50 fossils of unidentified hare species (Lepus sp.) that probably also were antelope jack rabbits have been found at many sites in Florida, dating to the early Pleistocene and the Pliocene.  The early Pleistocene/late Pliocene climate was much drier than it is today, and desert grassland habitat was more prevalent.  Several species of pronghorns lived in the southeast as well.  Antelope jack rabbits gradually declined in abundance and may have disappeared from the southeast completely by the late Pleistocene, but the fossil record is so incomplete that there is no way of knowing exactly when they became extirpated from the region.

Antelope Jackrabbit
The antelope jack rabbit prefers arid habitat and does not need water.  It gets enough moisture from the plants it eats.
 
Antelope Jackrabbit area.png
Modern day range of the antelope jack rabbit.  During the Pliocene and early to mid Pleistocene, it lived as far east as Florida.  It now is relegated to relic status.
 
The antelope jack rabbit’s favorite present day habitat looks like this.  They are most abundant in mesa type vegetation.
 
There are probably several factors explaining the decline of this once more widespread species.  About 300,000 years ago, a prolonged interglacial climate phase occurred.  During interglacials, precipitation increases, causing forests, woodlands, and wet meadows to predominate over arid grasslands.  Antelope jack rabbits are absent from fossil sites in Florida that date to after this prolonged interglacial.  However, this doesn’t mean they became completely extirpated in the region. Antelope jack rabbits may have persisted in relic populations in sandhill areas where the conditions allowed the continued existence of dry scrub habitat.  But these isolated populations would have been more susceptible to diseases.  Tularemia, also known as rabbit fever, is caused by the bacterium, Francisella tularensis.  It is spread through ticks, deer flies and other insects.  This plague causes a high fatality rate among all species of lagomorphs, and there are some regions of the antelope jack rabbit’s present day range where the disease has completely eliminated local populations.  Incidentally, hunters should wear gloves and surgical masks when cleaning rabbits.  If untreated, tularemia has a 7% fatality rate among humans.
 
Climate change combined with disease may have wiped out antelope jack rabbits in the southeast, but if there were still any surviving populations here during the late Pleistocene, the extinction of the megafauna would have been the final blow.  Jack rabbits favor overgrazed habitat. The trampling, feeding, and defecating of large mammals increases the types of forbs and other plants that jack rabbits like to eat.  Herds of mammoth, bison, and horses certainly overgrazed the landscape.  Without the presence of these species, jack rabbit habit was further degraded.
 
Though there were similarities between the modern day arid grasslands of the southwest and the early Pleistocene environment of the southeast, they were not exactly the same.  In the southeast the range of the cottontail rabbit and the antelope jack rabbit overlapped.  Today, the ranges of these 2 species do not overlap at all.  Antelope jack rabbits can live without ever drinking water.  They can get all the moisture they need from their diet which includes green grass, mesquite, and cactus.  (Insects are ingested accidentally.)  Therefore, they can live in areas where water was scarce.  But water holes did exist in Florida during the early Pleistocene, though they were less abundant than they are today.  Alligators, raccoons, and river otters all occur in the early Pleistocene fossil record of Florida.  So antelope jack rabbits did formerly occur in areas where water sources were more available.  This is evidence that some Pleistocene environments just have no modern analogue.

Southeastern Giant Beavers of the Pleistocene have been Declared a Distinct Species from Northern Giant Beavers

December 5, 2014

The giant beaver of the Pleistocene was semi-aquatic like its modern living cousin (Castor canadensis), but it ate different plant foods, and therefore occupied a different ecological niche.  Giant beaver fossils are fairly common throughout the midwest but have also been found at numerous localities in the southeast, particularly Florida.  Scientists formerly thought southern giant beavers were the same species (Casteroides ohioensis) that ranged throughout the midwest and northeast.  The reason for this misconception was the lack of complete skulls in the collections of southern museums.  Skulls of giant beavers were excavated from the Leisey Shell Pits in Florida, but this site dates to the early Pleistocene, and paleontologists thought they represented a species that was ancestral to the late Pleistocene giant beaver, thus explaining the differences in skull characteristics.  However, a complete skull resembling those early Pleistocene giant beavers was discovered in the Cooper River in South Carolina, and this was from a late Pleistocene deposit.  Recently, paleontologists got their hands on 2 more giant beaver skulls dating to the late Pleistocene of Florida.  Scuba divers found 1 in Lake Rousseau, and the other was found in the Aucilla River.  After a careful anatomical analysis, scientists determined the late Pleistocene giant beaver of Florida, coastal Georgia, and coastal South Carolina was a different species than the giant beaver of the midwest and northeast.  They gave it the scientific name Casteroides dilophidus.

Photo: Giant Beaver, Castoroides ohioensis.

Size comparison between the Pleistocene giant beaver and the extant beaver.  The 2 species co-existed for 2 million years.  Scientists recently realized there were 2 different species of giant beaver–a northern and a southern.

Casteroides dilophidus had a shorter ridge on the top of its skull than C. ohioensis.  This ridge is known as the saggital crest.  One of its skull sutures bears in a different direction than that same suture on C. Casteroides, and C. dilophidus’s cheek row teeth are located differently in relation to the zygomatic arch.  The projection of the frontal bone of the eye socket is “better developed” in C. dilophidus than in C. casteroides, according to the study.  Some C. dilophidus specimens have grooves in their teeth that are never found in C. casteroides, but this can’t always be used as a distinguishing characteristic.  The authors of the study don’t have enough data to determine whether giant beaver fossils found in the mid-south (Alabama, Arkansas, Mississippi, and Tennessee) belong to C. dilophidus or C. ohioensis, so they suggest classifying those specimens as Casteroides sp.  Many fossil specimens (mostly teeth) of Casteroides have been found in the mid-south but no complete skulls.

Casteroides preferred treeless freshwater marshes where they could feed on the aquatic plants that flourished in full sunlight.  Wooded swamps and bottomlands are too shady for the plants they liked to eat.  Much erroneous speculation surmises modern extant beavers outcompeted Casteroides.  Instead, the smaller species of beaver created habitat favorable to Casteroides.  Extant beavers fell trees and open up the forest canopy, allowing succulent shade-intolerant vegetation to thrive.  Old beaver ponds eventually become filled with sediment and are converted to the wet treeless marshes Casteroides required.  Moreover, Casteroides co-existed with Castor canadensis for 2 million years.

An ecological cycle of alternating beaver species during the Pleistocene is apparent.  Castor canadensis converted wooded swamps and bottomlands to treeless marshes.  When trees became scarce, Castor canadensis would abandon the locality while Casteroides would move in. But Casteroides didn’t eat trees, allowing the forest to grow back. Castor canadensis would then recolonize the location as Casteroides moved away in search of a more open habitat.  The presence of both species in the fossil record reflects a varied environment and a much more diverse ecosystem than exists today.

Reference:

Hulbert, R. C.; A. Kirne, and G.S. Morgan

“Taxonomy of the Pleistocene Giant Beaver Casteroides (Rodentia: Casteroidae) from Southeastern U.S.”

Bulletin of the Florida Museum of Natural History 53 (2) 2014

 

The Cat Food Scavenger

December 1, 2014

I prepared baked chicken for supper 2 weeks ago.  American chickens are nice and fat but for some dishes they are too fat.  I removed the skin from the chicken pieces before rolling them in cracker crumbs and black pepper.  This reduces the unwanted grease that nutritionists claim clog our arteries.  However, I hate wasting food, so I boiled the chicken skins and put some of them with the broth in a bowl for the cat.  I placed the bowl on the back step.  A few minutes later, I looked out the window to see if the cat was enjoying his warm treat on such a frosty night.  Instead, an unidentifiable gray object was over the bowl.  I turned on the light and saw an opossum.  I ran to fetch my camera, but when I opened the door, the creature scurried away quickly, a piece of chicken skin dangling from its mouth.    Later, the possum returned and I took a decent photograph of it.

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I discovered this opossum eating food I put on the back step for my cat.

The feral cat that I tamed (see:http://markgelbart.wordpress.com/2014/06/24/mr-claw/) used to eat every speck of food I placed outside.  But now that he realizes I’m going to feed him everyday, he doesn’t devour every bit at once.  There’s no telling how often that opossum has been scavenging cat food.  Possums are quite common in my neighborhood.  Several weeks ago, I saw a road-killed possum down the street that a flock of vultures made disappear in less time than it took me to jog 3 miles.

The Virginia opossum (Didelphis virginiana) is an amazing survivor.  Opossum remains are found in just about every Pleistocene-aged fossil site in Georgia, and they are still abundant today.  Their rapid rate of reproduction is their most important survival attribute.  They become sexually mature at 6 months, and their gestation period is less than 2 weeks.  They produce up to 18 young but the females only have 13 nipples.  An average of 7 young survive to adulthood.  Nevertheless, in about a year’s time 2 opossums can result in roughly a 20 fold increase.  When attacked by a large predator, opossums can escape by climbing a tree.  Their prehensile tails allow them to hang upside down from branches, giving them a good view of potential threats.  If they are unable to make it to a tree when attacked, their nervous system becomes overwhelmed, and they literally shit and faint.  The noxious fluid that leaks from their anus makes them unappetizing to predators.  Unless a predator is especially hungry, the lack of movement and bad smell will cause them to lose interest.  The opossum then recovers and goes on with its business.

Opossums are also omnivorous–another contributing factor to their success as a species.  They eat fruit, carrion, insects, worms and grubs, birds and eggs, small mammals, reptiles, and even venomous snakes.  They are immune to rattlesnake venom.  A recent study found there is an evolutionary arms race between opossums and pit vipers.  Scientists discovered opossums have rapidly evolving gene codes for Von Willibrandt’s Factor, an important blood-clotting protein targeted by snake venom.  Natural selection has strongly favored those individuals of the opossum population immune to snake venom.  Creationists often use “living fossils” such as the opossum as evidence that evolution doesn’t occur.  They are wrong.  Although the modern Virginia opossum is anatomically identical to the opossum of 3 million years ago, its physiology has evolved considerably.  If we could bring an opossum from 2 million years ago to the present, it would likely not be able to survive the bite of a modern day rattlesnake like its modern day descendents can.

The opossum is 1 of the oldest species of North American mammals.  Ancestral opossums first evolved about 65 million years ago when the dinosaurs became extinct.  This is also the time when the shared ancestry of American opossums and Australian marsupials diverged.  These ancestral species of opossums became extinct in North America about 25 million years ago, but they continued to live in South America which at that time had become an island continent.  A landbridge emerged 3 million years ago, connecting North and South America, and this is when Virginia opossums moved north.  At least 103 species of opossums live in South America, but only 1 evolved the ability to survive in the temperate climates that occur in North America.  All the other species are restricted to tropical climates.  There are 5 other species of opossums in the Didelphis genus that are closely related to the North American opossum.  There are also 4-eyed opossums (they don’t actually have 4 eyes), 14 species of woolly opossums, 20 species of short-tailed oppossums, 56 species of diminutive mouse opossums, and a water opossum well adapted to a semi-aquatic existence.

Reference:

Jansa, Sharon A.; and Robert Voss

“Adaptive Evolution of the Venom-Targeted vWF Protein in Opossums that eat Pit Vipers”

Plos One 6 (6) 2011

The Reddick Fossil Site in Marion County, Florida

November 26, 2014

One could almost refer to the Reddick Fossil Site in Florida as Rancho La Brea east.  It’s one of the richest eastern sites in species diversity, but nevertheless falls far short of Rancho La Brea’s treasure chest of fossils.  At least 147 species of vertebrates were recovered from Reddick compared to 231 from Rancho La Brea and the latter also far surpasses the former in quantity. Moreover, Rancho La Brea is still being excavated.  The Reddick Fossil Site was an abandoned limerock quarry excavated during the early 1960’s.  The Pleistocene topography consisted of limesink lakes and caverns with a soil chemistry that helped preserve the bones of many animals.  Owls roosted in the caves during the Pleistocene, and bones from the small mammals and birds they ate were found in their fossil pellets.  The composition of species shows that a wide variety of habitats occurred locally, including woodland, grassland, and wetland.  The fossil remains are thought to date to between ~200,000 BP- ~114,000 BP.  The presence of glyptodont, vampire bat, ocelot, and giant tortoise is evidence of a climate at least as warm as today’s Florida, even though this period of time includes the Illinois Ice Age.  This is the only site in southeastern North America where ocelot fossil remains have been found.  Only 32 of the 147 species are extinct.  Many of the large mammals were probably overhunted by man into extinction, and we know for sure passenger pigeons were.  However, some of the bird extinctions were local species that became extinct during marine high stages of the Sangamonian Interglacial when much of their terrestrial habitat was lost to high sea levels.  The following is the Reddick Fossil Site faunal list from the below referenced work.  * denotes extinct species.  + indicates an extant species no longer native to Florida.  The remarkable thing about this list is how few reptiles have gone extinct.  This suggests little environmental change in this region over the past 200,000 years.  (I’m not including the scientific name for most of these entries.  I feel lazy today and it’s almost a holiday.  Happy Thanksgiving.)

Map of Florida highlighting Marion County

Marion County, location of 1 of the best Pleistocene fossil sites in southeastern North America.

Greater siren

Mud siren

Ambystoma sp. (a type of salamander)

eastern spadefooted toad

oak toad

common toad

narrow-mouthed toad

tree frog sp.

leopard frog

Pseudemys sp. (a type of slider/cooter turtle)

box turtle (Terrepene carolina putnami)–an extinct subspecies but extant species

gopher tortoise

*medium-sized land tortoise–Hesperotestudo incisa

*giant land tortoise–H. crassicutata

soft-shelled turtle

green anole lizard

eastern race runner

5-lined skink

common glass lizard

Florida worm lizard

eastern ring-necked snake

mud snake

yellow-lipped snake

eastern hog-nosed snake

southern hog-nosed snake

rough green snake

black racer

coachwhip snake

indigo snake

king snake

corn snake

rat snake

pine snake

crowned snake

brown snake

garter snake

coral snake

pygmy rattlesnake

Rattle.jpg (68536 bytes)

 

 

 

 

 

 

All of the species of snakes found at the Reddick fossil site were still relatively common when Columbus reached North America

eastern diamondback rattlesnake

alligator

pied-billed grebe

*extinct grebe, a diver in the podiceps genus

mottled duck

pintail duck

shoveler

blue-winged teal

green-winted teal

ring-necked duck

*extinct condor–Gymnogyps amplus

turkey vulture

*extinct vulture–Coragyps occidentalis

Cooper’s hawk

sharp-shinned hawk

red-tailed hawk

red-shouldered hawk

peregrine falcon

sparrow hawk

caracara

quail

*extinct quail–Neotyx pennisubali

turkey

Virginia rail

sora

*extinct rail–Porzana auffenbergi

yellow rail

*extinct rail–Laterallus guti

*extinct coot–Fuliza merm

common crow

fish crow

blue jay

*extinct jay–in protocitta genus

house wren

*extinct wren–Gasthothanus brevs

maryland yellowthroat

cowbird

red-winged blackbird

grackle

eastern meadowlark

rufous-sided towhee

Henslow’s sparrow

Henslow

Henslow’s sparrow.  This species prefers weedy grassland habitat.  Ducks and rails prefer wetlands.  Passenger pigeons and woodpeckers need woodlands.  The composition of birds reflects varied habitats near this locality during the Pleistocene.

killdeer

lesser yellowlegs

common snipe

*passenger pigeon

mourning dove

barn owl

screech owl

burrowing owl

barred owl

yellow-shafted flicker

red-headed woodpecker

eastern kingbird

purple martin

*extinct swallow–Tachycinctus spelodytes

oppossum

*vampire bat–Desmodus stockii

southeastern myotis

red bat

Florida yellow bat

Brazilian free-tailed bat

*Wheatley’s ground sloth–the evolutionary ancestor of Jefferson’s ground sloth

*Harlan’s ground sloth

*Beautiful armadillo

*pampathere–a giant armadillo

*glyptodont

marsh rabbit

cottontail rabbit

southern flying squirrel

undetermined squirrel in scurius genus–probably a gray squirrel

southeastern pocket gopher

rice rat

harvest mouse

old field mouse

cotton mouse

Florida mouse

golden mouse

cotton rat

wood rat

pine vole

round-tailed muskrat

*Florida bog lemming–Synaptomys australis

*dire wolf

+coyote

gray fox

*Florida spectacled bear–Tremarctos floridanus

black bear

raccoon

+hog-nosed skunk

spotted skunk

striped skunk

+jaguar

cougar

+ocelot

aka, the dwarf leopard,

Reddick is the only fossil site in southeastern North America where remains of an ocelot have been found

bobcat

saber-tooth–Smilodon fatalis

mastodon

mammoth

+horse

*tapir

*long-nosed peccary

*flat-headed peccary

*large-headed llama

*stout-legged llama

white-tailed deer

bison

Reference:

Gut, James H.; and Clayton Ray

“The Pleistocene Vertebrate Fauna of Reddick, Florida”

Quarterly Journal of the Florida Academy of Science 1964

 

African Hunting Dogs Lived in North America during the Middle Pleistocene

November 21, 2014

The African hunting dog (Lycaon pictus meaning painted wolf) stars in many nature documentaries, but few people are aware that close relatives of this species formerly lived across Eurasia and even into North America.  At least 2 different species occurred in North America during the middle Pleistocene between ~1.5 million BP-~300,000 BP.  Fossil remains of Xenacyon lycaonoides were excavated from 2 sites in Alaska and 1 in the Yukon.  The first paleontologist who looked at these specimens misidentified them as dhole (Cuon alpinus) teeth, but a more recent examination of the dentition determined they belonged to a canid more closely related to African hunting dogs.  These scientists also examined the only other dhole fossils found in North America (from San Josecitos Cave in Mexico) and did confirm that identification.  The other American species of canid closely related to the African hunting dog was Xenacyon texanus, and it’s known from just 1 fossil locality–Rock Creek in northwest Texas.  The sum total fossil remains of X. texanus are part of 1 jaw with teeth, a leg, and a shoulder fragment.  Based on this scant anatomical material, scientists believe X. texanus was slightly larger the X. lycaonoides which was about the size of a timber wolf.

Photo: An African wild dog with pups

Two extinct and little known species of canid, closely related to present day African hunting dogs, lived in North America during the middle Pleistocene.

Dholes tearing up a deer.  Fossil remains of this canid have been found from just 1 site in North America.  It originated in Asia, yet it inhabited Mexico during the late Pleistocene.  It must have been more widespread in North America than the fossil record indicates.

Wolf fossils in North America are much more common than those of X. lycaonoides, X. texanus, and Cuon alpinus.  This suggests these species of hunting dogs didn’t compete well with American wolves.  During the middle Pleistocene X. texanus would have occupied the same ecological niche as Armbruster’s wolf (Canis armbrusteri), the probable evolutionary ancestor of the dire wolf (Canis dirus).  Nevertheless, X. texanus did live in North America long enough to have evolved into a different species from X. lycanoides.  Obviously, they were more widespread and successful than the fossil record indicates.  It’s possible this species persisted into the late Pleistocene but was restricted to regions where their remains were not likely to be preserved.  The only dhole fossils found in North America were discovered in Mexico, yet this species originated in Asia, crossed the Bering landbridge, and must have occupied large areas of North America before colonizing Mexico.  Dholes co-existed with dire wolves and timber wolves (Canis lupus) in North America for some undetermined length of time.  The oldest dire wolf fossil dates to 252,000 BP (from a uranium-series dated deposit in South Dakota).  Timber wolves crossed the Bering landbridge 100,000 years ago and co-existed with dire wolves in western North America until the end of the Pleistocene.  It’s not known when dholes crossed the Bering landbridge.  Timber wolves and dholes are not known from the fossil record of southeastern North America.  I think dire wolves kept these other big game-hunting canids from occupying this more wooded region where prey was less abundant than on the grassy plains of the west.

The Rock Creek Fossil Site

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Rock Creek, the only known fossil site where Xenocyon texanus has been found, is located just north of Plainview, Texas, represented by the dot on this map.

The Rock Creek fossil site is located just north of Plainview, Texas.  This is the only locality where remains of X. texanus have ever been found.  E.L. Troxell excavated this rock quarry and published his findings in 1915.  Along with the rare canid, he found the remains of gopher tortoise, giant tortoise, Harlan’s ground sloth, glyptodont, Imperial mammoth, flat-headed peccary, camel, llama, Soergel’s musk-ox, and horse.  He identified the remains of another canid as dire wolf, but he was probably in error.  The geological formation where these fossils were found is thought to be no younger than 400,000 years BP.  Dire wolves probably didn’t evolve yet, so the canid remains probably should be referred to as Armbruster’s wolf.

The composition of species excavated from Rock Creek suggests the region during this climatic phase consisted of arid grassland and scrub with milder winters than those of today.  Some scientists assume it was frost free due to the presence of giant tortoise, but I believe this species could survive light frosts.  Although winters were warmer then, it’s not safe to assume there were no frosts.  The horses, camels, and peccaries likely served as dinner for X. texanus.

References:

Tedford, Richard; et. al.

“Philogenetic Systematics of North American Fossil Caninae (Caninae: canid)”

Bulletin of the American Museum of Natural History 2009

The Pleistocene Box Turtle (Terrapene carolina putnami)

November 18, 2014

I self torture myself every Wednesday: I go in my backyard and do 150 pullups, jogging in place between sets, and I follow this exertion with yardwork such as cutting the grass with a scythe or chopping firewood with a dull axe.  (Lawnmowers and chainsaws are noisy and unpleasant and I use neither.)  Three weeks ago while torturing myself, I discovered a male box turtle (Terrapene carolina) sitting on the edge of a shallow burrow consisting of leaf litter and pine straw.  I didn’t think this would be sufficient cover to protect a cold blooded reptile from forthcoming frosts.  Yet, this turtle was still alive after the first frost of the year.  I perused the scientific literature and learned from 1 study that the average depth of a box turtle’s winter burrow in Ohio is only 2 inches, though some burrow as deep as 7 inches.  Snow further insulates them.  Box turtles range as far north as Maine and apparently they can survive when their body temperatures fall below freezing.  However, winter freezing is their leading cause of mortality.  Hard winters diminish their populations to some degree.

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A male box turtle that may spend the winter in my backyard.  Male box turtles have red eyes.  Females have yellow eyes.

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Note the burrow into the leaf litter and pine straw behind the turtle. Despite their terrestrial existence, box turtles are more closely related to aquatic turtles than land tortoises.

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Also note how shallow this burrow is.  Box turtles can survive hard freezes covered by just 2 inches of leaf litter and/or soil.

Various climatic fluctuations during the Pleistocene isolated populations of box turtles.  These changing conditions resulted in the regional variations in box turtle morphology evident today.  There are 6 recognized subspecies of eastern box turtle: the eastern (T. c. carolina), the Florida (T.c. bauri), the 3-toed (T.c. trungus), the Gulf Coast (T.c. major), the Mexican (T.c. mexicana), and the Yucatan (T.c. yucatan).  Moreover, there was a large extinct species (T.c. putnami), known from Pleistocene fossil sites.  All of these subspecies readily hybridize on the borders of their ranges.  A late herpetologist, William Auffenberg, and others hypothesized T.c. putnami preferred warm coastal grasslands, while T.c. carolina inhabited forested landscapes.  Accordingly, fossil remains of T.c. putnami could be used as evidence that a particular fossil site was of an interglacial age, and the presence of T.c. carolina was evidence a specific site was of glacial age.  But some remains of T.c. putnami were found at the Jones Creek fossil site in Missouri which dates to a climatic phase when jack pine and grass dominated the local flora.  Jack pine no longer occurs south of Michigan, and its presence in Missouri is evidence of a cooler climate than that of today.  I don’t believe Dr. Auffenberg’s hypothesis is valid.  T.c. putnami was widespread during the Pleistocene and likely well adapted to both glacial and interglacial conditions.

Partial carapace of the extinct subspecies of box turtle, T. carolina putnami.  Too bad the colors have faded away.

A recent comprehensive study of box turtle morphology and genetics determined that there was no evidence for the existence of the Gulf Coast subspecies, T.c. major.  Instead, the authors of this paper suggest box turtles found on the Florida panhandle, thought to be this subspecies, are descended from hybridization between the eastern subspecies, T.c. carolina, and the extinct subspecies,  T.c. putnami.  This would explain the larger size of Gulf Coast box turtles compared to other subspecies.  For some undetermined ecological reason the once widespread Pleistocene ecomorph of box turtle still occured as a relic population in this region, and the survivors hybridized with another now more common subspecies.

Box turtles are amazing survivors.  They are omnivorous, capable of eating any plant matter such as fruit, flowers, and fungi; and animal matter including insects, worms, snails, birds’ eggs, and carrion.  And they can survive scarcity of food because they have slow metabolisms.  They can live to be 100 years old and can regenerate when severely burned.  Females can mate once and lay fertile eggs for 4 years.  Box turtles survived millions of years of climatic fluctuations and still live and can be found in my backyard.

References:

Austin, Jones; et al

“Morphological and Molecular Evidence Indicate that Gulf Coast Box Turtles (T.c. major) are not a Distinct Evolutionary Lineage in the Florida Panhandle”

Biological Journal of the Linnean Society 2011

Claussen, Denis; et al

“Hibernation in the Eastern Box Turtle, Terrapene Carolina

Journal of Herpetology 25 (3) 1991

The Destruction of a Beautiful Kettle Lake led to the Origin of JP Morgan-Chase Bank

November 13, 2014

Kettle lakes are common geological formations found in North America in any region once covered by a glacier.  When glaciers recede they often leave large chunks of ice behind.  Both wind and water borne sediment covers these blocks of ice, temporarily insulating them, but eventually the ice melts and forms a lake.

Diagram showing how a kettle lake forms.

20,000 years ago, the edge of a mighty glacier advanced as far as what today is Manhattan Island, New York.  A narrow strip of unglaciated land, about 50 miles wide, existed on the continental shelf between Manhattan and the Atlantic Ocean.  After the glacier receded it left a kettle lake behind on the southern end of Manhattan.  The lake held clear glacial meltwater and was continuously fed by underground springs.  It was 70 feet deep–evidence the block of ice left behind had been quite large.  For thousands of years, Indians used this lake as a source of freshwater because the rivers surrounding Manhattan are tidal in nature and too salty to be potable.  An Indian settlement existed on the southwestern edge of the lake in 1604 when the Dutch first established a colony on Manhattan.  The Dutch called the lake “Koelch,” meaning small body of water, but when the English took over the island, the word was mispronounced, and thereafter was called “Collect Pond.” A steep 110 foot tall hill, known as Bayard’s Mount, occurred on the north side of Collect Pond, and another steep hill, Kalch Hoek, bordered the west side.  A freshwater marsh existed to the south of Collect Pond, and 2 creeks served as outlets for the kettle lake’s overflow.  Lispenard Creek drained into the Hudson River and Old Wreck Brook drained into the East River.  Fish likely colonized Collect Pond through these creeks.  Species of fish recorded to have lived in Collect Pond included pumpkinseed sunfish, redfin pickerel, eel, and killifish. Collect Pond was a beautiful and valuable natural resource.  It provided fresh drinking water for all of Manahattan for almost 200 years, as well as winter ice skating, and summer recreational fishing.  Man then turned this heaven into hell.

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A portrait of Collect Pond painted in 1798 by Archibald Robertson.  The weeping willow is not a native species and must have been planted early in the century.  After  poison from a tannery polluted the pond, developers filled it in with dirt from the hill (Bayard’s Mount) in the foreground.  That hill also no longer exists.

Circa 1800, the stupid greedy owner of a tannery factory was responsible for dumping tannins into Collect Pond, poisoning New York City’s drinking water.  Because Collect Pond no longer provided drinkable water, city leaders decided just to fill in the lake with dirt from the beautiful surrounding hills, thus destroying this once pristine site forever.  They called this leveled land “Paradise Square,” but within decades it transmogrified into the infamous 5 Points neighborhood depicted in the violent movie Gangs of New York.  To make matters worse, organic plant material from the fill material rotted away, causing parts of the neighborhood to sink.  It was a muddy, disease-ridden slum.  Anybody with any money at all moved away, leaving the neighborhood populated by poor Irish immigrants and freed African-Americans.  Circa 1900, city leaders condemned the neighborhood and replaced it with the city municipal building where justice and injustice are still dispensed by the court.  (Other buildings and parking lots occupy the rest of the space.)

The Manhattan Municipal Building towers 25 stories high, with an additional 15 stories on the center spire. (Amal Chen/The Epoch Times)

The New York City Municipal Building now stands where Collect Pond used to be. 

 

 Aaron Burr was the Vice-President of the United States between 1800-1804.  In 1808 he responded to the ecological disaster of Collect Pond by founding the Manhattan Water Company.  His stated goal was to bring water from upstream to downtown, but instead he used the assets to start JP Morgan Bank.  The city eventually built an aqueduct to bring water from a source off the island.  Aaron Burr is best known for his duel with Alexander Hamilton.  Burr fatally wounded Hamilton in 1804.  Hamilton was the Secretary of the Treasury and a member of Thomas Jefferson’s cabinet.  Fighting duels was a childish custom.  Imagine if Joseph Biden challenged Hillary Clinton to a duel.  JP Morgan is still run by childish crooks, but at least they don’t fight duels.

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Portrait of the duel between Aaron Burr and Alexander Hamilton in 1804 drawn by J. Mund.  Aaron Burr founded JP Morgan for the purpose of funding a project to supply fresh water to New York City after Collect Pond was poisoned.  This portrait is not accurate.  The seconds had their backs turned so they wouldn’t have to testify in court as witnesses.

Reference:

Sanderson, Eric

Mannahatta: A Natural History of New York City

ABRAMS 2009

Georgia’s National Champion Trees

November 10, 2014

The nice trees I observed on Berry College campus last week inspired me to study the inventory of Georgia’s National Champion Trees published by the Georgia Forestry Commission (available online http://www.gfc.state.ga.us/forest-management/champion-tree-program/).  Georgia has 20 national champion trees.  Foresters measure the circumference at 4.5 feet above the ground + height + crown width to determine whether a tree is a champion of its species.  Some species have a range that is restricted to Georgia, so of course, the national champion of that species would be found in state.  The Georgia plume (Elliotia recemosa) is a small rare tree known from just 9 sites in the Georgia sandhills.  The largest known Georgia plume is in Tattnall County and is 47 feet tall with a diameter of a foot.

Other species have a limited regional range but are most common in Georgia, so the champion of that species would be expected in state.  Georgia oak (Quercus georgiana), first discovered on Stone Mountain in 1840, is a species of red oak that grows on rocky outcrops in the southern Appalachians.  The national record Georgia oak is found in Clarke County and is 59 feet tall with a diameter of just over 2 feet.  The Oglethorpe oak (Q. oglethorpensis), a species of white oak not recognized till 1940, includes a population of less than 1000 specimens in disjunct locations primarily on the Georgia Piedmont but also in Mississippi and South Carolina.  The record tree of this species is found in Oglethorpe County and is 64 feet tall with a diameter of over 3 feet.  Nutmeg hickory (Carya myritieformis) is another regionally rare tree with disjunct populations.  The largest known specimen is found in Floyd County and is 115 feet tall with a diameter of about 2 feet.

Some species of trees are fairly common throughout the southeastern coastal plain, but the largest specimens are found in Georgia.  Ogeechee lime (Nyssa ogeche), a tupelo with an edible fruit, is most common in Georgia.  The largest known is found in Toombs County and is 45 feet tall with a diameter over 6 feet.  Swamp privet (Foresteria acuminata), a member of the olive family, grows throughout the southeastern coastal plain.  The largest known specimen, also found in Toombs County, is 47 feet tall with a diameter of 11 inches.  Chalk maple (Acer leucoderma) is a rare regional tree found on the inner coastal plain and piedmont.  The largest specimen is found in Greene County and is 64 feet tall with a diameter of a foot.  Florida maple (Acer barbatum) is a little more widespread than chalk maple.  The largest known Florida maple is found in Floyd County and is 91 feet tall with a diameter of almost 4 feet.  May hawthorne (Crataegus aestivalis), produces a fruit used in making jelly.  The largest known is found in Haralson County and is 40 feet tall with a diameter of over 1 foot.  Viburnum possumhaw (V. nudem) is another regional borderline shrub with a record specimen found in Georgia.  The largest known is found in Oconee County and is 33 feet tall with a diameter of 4.4 inches.  Aloe yucca (Yucca aloensis) grows in coastal scrub along the southeastern coast as far north as New Jersey.  The largest known is found in Brantley County and is 14 feet tall with a diameter of 6 inches.

Myrtle oak (Q. myrtifolia) ranges mostly in Florida but the northernmost population in Camden County, Georgia holds the record specimen which is 36 feet tall with a diameter of 9.5 inches.

The most impressive national record trees in Georgia are from species found across most of eastern North America.  The largest red mulberry (Morus rubra) is found 20 minutes from my house in Richmond County.  It is 54 feet tall with a diameter of over 7 feet–truly an impressive tree harking back to primeval times.

This national champion red mulberry tree is located about 20 minutes from my house in Richmond County.

A post oak (Q. stellata) in Jackson County is 86 feet tall with a diameter over 6 feet.

The national champion post oak is in Jackson, County, Georgia.

National champion Ogeechee Lime Tupelo in Toombs County.

A southern red oak (Q. falcata) in Upson County is 137 feet tall with a diameter of 9 feet.  Unfortunately, there’s no photo of it online.  An eastern red cedar (Juniperus virginiana) growing in a Coffee County cemetery is 54 feet tall with a diameter of over 6 feet.

National champion Eastern Red Cedar growing in the Lane Hill United Methodist Church Cemetery, Coffee County, Georgia.

The largest Alabama black cherry (Prunus serotina alabamensis), a subspecies of black cherry, is found in Floyd County and is 49 feet tall with a diameter of 9 inches.  This is much smaller than the state record black cherry found in Ellijay which is 83 feet tall with a diameter of over 5 feet.

Georgia has some champion specimens of common borderline shrubs too.  The largest flatwoods plum (Prunus umbellata) is found in Union County and is 43 feet tall with a diameter of 11 inches.    The largest smooth sumac (Rhus glabra) is found in Twiggs County and is 52 feet tall with a diameter of 11 inches.  The largest mountain laurel (Kalmia latifolia) is found in Fannin County and is 20 feet tall with a diameter of almost 20 inches.  The largest buttonbush (Cephalanthus occidentalis), favorite food of the mastodon, is found in Screvin County and is 22 feet tall with a diameter of 5 inches.

Some of the most impressive trees in Georgia are not national record trees.  Below are photos of a few.

Georgia’s state champion black oak is located next to a convent in Fulton County.  William Bartram walked through a forest of gigantic oaks, some larger than this.  Too bad, pioneers destroyed that forest.

Georgia’s state record eastern cottonwood also located in downtown Atlanta.

Georgia’s state record beech is located in Lawrenceville, Georgia where my grandfather lived until he was 16.

The 2nd highest scoring trees in Georgia are bald cypresses.  

The highest scoring tree in Georgia is this live oak in Ware County.

The black oak growing next to the convent is over 7 feet in diameter.  This is not as large as many of the black oaks William Bartram observed in a 7 mile long forest he traveled through in 1775 (See: http://markgelbart.wordpress.com/2011/04/11/william-bartrams-magnificent-forest/)  Some of those trees measured 11 feet in diameter.  Loggers destroyed most of Georgia’s forests between 1865-1945.  The primeval forests prior to the Civil War undoubtedly held specimens larger than today’s state and national champions.  However, we are living during a climatic phase favorable to the rapid growth of trees.  The largest tree specimens lived during interglacials and interstadials when CO2 concentrations and precipitation levels were high.  If we preserve enough green space on fertile ground and allow remaining old growth forests to remain intact, there is hope that trees such as Bartram encountered may grow once again.


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