PREHISTORIC LIFE HOME PREHISTORIC LIFE TABLE OF CONTENTS OBL HOME OBL REFERENCES

NUMBERS OF SPECIES:

There are about 1.5 million species which are known to exist on earth.  The number of as yet undescribed species is probably greater than the number already known to exist.  Here are the statistics on the known number of species according to the biological group.

1) Bacteria: 4,800 sp.

 

2) Protists:

--Algae: 26,900

--Protozoa: 30,800

3) Fungi:

--69,000

4) Plants:

--248,400

5) Animals:

--sponges: 5,000                   --corals & jellyfish: 9,000

--various worms: 36,200                  --molluscs: 50,000

--starfish & relatives: 6,100

--arthropods other than insects: 123,400

--insects: 751,000

--It is estimated that the number of undiscovered species of insects exceeds the total number of species of all organisms.

--fish: 25,000             --amphibians: 4,000

--reptiles: 6,500      --birds: 8,500   --mammals: 4,000

-There are even new species of mammals that continue to be discovered: 1988-90 3 sp. of primates discovered; 1991 a new whale sp. was identified (and another sp. has been sighted but not yet identified); a new sp. of Vietnamese deer was discovered in 1995.

BIOMES

     Why are there so many types of species? One reason is that the types of environments differ in different parts of the world.   Even in one region of a single continent, southern South America for example, there is a great diversity in natural environments.  One would not find the same species of plants and animals in the Andes,

andes andes
the thorn forest-scrubland of the Chaco in Paraguay,
chaco
the coastal environments of Chile (with its colonies of comorants and sea lions),
chile
tropical rainforests,
rainforest
and subtropical rainforests.
rainforest  
The aquatic environments of the United States
have very different species than the those found in the aquatic environments in South America.
lily pads

    Throughout the world, there are classes of ecosystems referred to as biomes.  A biome is a major type of physical environment that is inhabited by characteristic plants and animals.  Temperature and annual precipitation determine the nature of many of these biomes.

a) deserts: Deserts actually contain a diversity of organisms.  Some are dormant until the rains come and others are nocturnal.

b) grasslands: In grasslands, the amount of rainfall is less than that needed to support trees. Herbivorous mammals and the insects they attract are important components of the animal life.

c) savanna: Savannas are extensive grasslands with occasional trees.  They are often tropical with rainy and dry seasons.

d) tropical rain forests: Tropical rainforests have high temperatures and a great amount of annual rainfall.   There is little seasonal change and, as a result, trees do not drop their leaves.  Because the trees do not drop their leaves and because insects and decomposers quickly make use of the organic matter on the forest floor, the soils are relatively poor with very few nutrients.  Tropical rainforests have an incredible biodiversity—an estimated half of all the plant and animal species on earth live here.  The following images are of a Brazilian rainforest (just south of Rio) and a subtropical rainforest in Paraguay (the national park Ybycui).

brazil ybycui
e) temperate deciduous forests: The dominant type of tree in temperate deciduous forests are the broad-leafed flowering plants which drop their leaves in colder seasons.  There is a lesser diversity of species than that found in tropical rainforests.
delaware woods
f) coniferous forests: Conifers have thin leaves (which we often call needles).  These needles allow them to lose less water which is especially an advantage in areas with harsh winters such as northern latitudes and higher altitudes (as in Colorado pictured below). 
colorado
g) tundra: The tundra has a permanently frozen soil layer and short plants.  It can be found in polar regions and at high altitudes (such as in the Andes below).
tundra

SPECIFICITY

     While some organisms are generalists, adapted to survive under a variety of conditions with a variety of food sources, many are specialists--they are adapted to a narrow set of conditions.  Sea lions only inhabit certain coastal regions of the world.

sea lions sea lions
These macaws are native to tropical forests of the Americas.
macaws
The tagua (collared peccary) is the largest wild pig in the world and exists only in an arid region of central South America known as the Chaco.
tagua
Most of the earth’s organisms only inhabit very restricted regions of the planet.  The following maps depict the restricted habitats of a variety of species.

A) Because biomes vary across the world or across the country, one finds many organisms occurring only in certain areas:

1) the east coast: great black-backed gull, surf & white-winged scoters, black-bellied plover, purple sandpiper, Louisiana heron, white ibis, glossy ibis, tufted duck, whistling swan, red-necked grebe,

2) the Northeast: chestnut-sided warbler, golden-winged warbler, alder flycatcher, magnolia warbler, black-throated green warbler, blackburnian warbler, black-throated blue warbler

3) grasslands: greater prairie chicken, gray partridge, lark bunting, chestnut-collared, McCown's, & Smith's longspurs, 

4) Fla:brown noddy, black noddy, magnificent frigatebird, swallow-tailed kite (Georgia also), wood stork, great white heron, limpkin, short-tailed hawk, everglade kite, spotted-breasted oriole, gray kingbird, blue-gray tanager, black-whiskered vireo, mangrove cuckoo, red-whiskered bulbul, smooth billed ani

5) Texas:whooping crane (50 individuals), least grebe, green kingfisher, white tailed hawk, black-capped vireo, jacana, scaled quail, chachalaca, pauraque, white-winged dove, cave swallow, golden-fronted woodpecker, black-headed oriole, kiskadee flycatcher, yellow green vireo, black-crested titmouse, buff-bellied hummingbird 

6) New England: common eider,  mourning warbler, spruce grouse, hawk owl, boreal owl, bay-breasted warbler, yellow throated flycatcher, gray-cheeked thrush, boreal chickadee, blackpoll warbler

 

--ENDANGERED SPECIES

     About one quarter of the earth’s mammals and reptiles, 21% of amphibians, 30% of fish, and 12% of the earth’s birds are in danger of extinction.  The loss of habitat is the greatest threat to 85% of the earth’s most threatened birds.  About 1/3 of parrot species are endangered by habitat loss and collecting for pets or plumage.

     Many populations now exist in such small numbers that they are in danger of extinction.  Some occur in New York such as the Indiana Bat, Karner Blue Butterfly, Piping Plover, Eastern Puma, Shortnose Sturgeon, Dwarf Wedgemussel and the Eastern Sandplain Gerardia (a flower).  The humpback and right whales and hawksbill, Kemps Ridley, Leatherback, and Loggerhead sea turtles are also in danger of extinction; they can be found off the coast of New York.  A number of New York species are threatened (not as critical as endangered) including the bald eagle, lynx, bog turtle, Chittenango ovate amber snail, and 4 species of plants.

 

I)                    MANY ENDANGERED SPECIES ARE FOUND ONLY IN CERTAIN PARTS OF THE WORLD

   The maps above depicted the limited distribution of many species globally.

 

II)                  MANY OF THE ENDANGERED ORGANISMS FOUND IN THE U.S. ARE SO SPECIFIC THAT THEIR HABITAT IS LIMITED TO ONE OR TWO STATES:

1)     MAMMALS

--Columbia White Tail Deer: WA & OR

--Key Deer: FL

--San Joaquin Kit Fox: CA

--Jaguarundi: one subspecies TX, the other AR

--Hawaiian Hoary Bat: HI

--Mariana Fruit Bat: Guam

--6 species of Kangaroo Rat (Fresno, Giant, Morro Bay, Stephens, Tripton, San Bernardino Merriams): CA

 

2)     BIRDS

--Hawaii has a great diversity of birds that occur only there an nowhere else in the world; those that are endangered include the Nihoa Millerbird, Palila, Moorhen, Nukupu’u, and two species of ‘O’u

--Puerto Rican parrot, Puerto Rican nightjar, Puerto Rican plain pigeon: Puerto Rico

--Northern Spotted Owl: CA, OR, WA

--Atwaters Greater Prairie Chicken: TX

--Cactus ferrugineous Pygmy Owl: AZ

--San Clemente Shrike, California Least Tern, California and Light Footed Clapper Rails: CA

--Guam Rail: Guam

--Florida Scrub Jay, Florida Grasshopper Sparrow, Cable Seaside Sparrow: Florida

 

3)     REPTILES

--Bluetail Skink, Sand Skink, Atlantic Saltwater Marsh Snake: Florida

--Almaeda Whipsnake, Giant Garter Snake: California

--Concho Water Snake: TX

--Lake Erie Water Snake: OH (and Ontario)

--Alabama Redbelly Turtle, Flattened Musk Turtle: Alabama

--Plymouth Redbelly Turtle: MA

--Yellow Blotched Map Turtle: MS

 

4)     AMPHIBIANS

--Barton Springs Salamander: TX

--Cheat Mountain Salamander: WV

--California Tiger Salamander: CA

--Red Hills Salamander: AL

--Shenandoah Salamander: VA

--Houston Toad: TX

--Puerto Rican Crested Toad: Puerto Rico

--Wyoming Toad: Wyoming

 

5)     FISH

--Pygmy and Smoky Madtom: TN

--Pahrump Poolfish, Devils Hole and Ash Meadows Pupfish: NV

--Comanche Springs Pupfish: CA

--Chum Salmon: VA

--Coho Salmon: CA

--Pygmy Sculpin and Cahaba Shiner: AL

--Cape Fear Shiner and Waccamaw Silverfish: NC

--Pecos Bluntnose Shiner: NM

--Little Coloroado Spinedace: AZ

--Steelhead: OR, WA

--June Sucker: UT

--Warner Sucker: OR

--Greenback Trout: CO

 

6)     INVERTEBRATES (Spiders and Clams as examples)

--Bone Cave Harvestman, Bee Creek Cave Spider, Tooth Cave Pseudoscorpion: TX

--Spruce-fir Moss Spider: NC, TN

--Speckled Pocketbook, Arkansas Fatmucket: AR

--Carolina Heelsplitter: NC & SC

--Louisiana Pearlshell: LA
–Cumberland Pigtoe: TN

--Dark Pigtoe: AL

--James Spinymussel: VA & WV
–Tar
River
Spinymussel: NC

 

7) PLANTS

--Brittons Beargrass, Amargosa Niterwort, White Birds in a Nest: FL

--San Clemente Island Bush Mallow, Santa Cruz Island and Island Malocothrix: CA

--Mohrs Barbaras Buttons: AL & GA

--a great diversity of plants native to Hawaii including many species of Alani

--Michigan Monkey-Flower: MI

--Macfarlanes 4-o’clock: ID, OR

--Fassets Locoweed: WI

--Brady Pincushion Cactus:AZ

--Peebles Navajo Cactus and San Rafael Cactus: UT

--Blowout Penstemon: NE

--Penland Beardtongue: CO

--Texas Trailing Phlox: TX

--Godfrey’s Butterwort: FL

 

LOSS OF HABITAT

plain
The above land in Paraguay was once subtropical forest, now it is pasture for cattle.
chile

This beautiful region of southern Chile was once temperate forest.

     Even in this region, the original habitat has disappeared.   Although the following pictures depict forests of the Northeast U.S., they are very different from the virgin old-growth forests full of hundred foot trees which once existed here.

woods woods