Leaf and Insect Fossils
from Florissant, Colorado
Lower Oligocene
35,000,000 Years ago

The following information is copied from the website of the Proctor Museum of Natural Science with permission.

Fossils are the evidence of things which lived long ago. Fossilization or petrification can be accomplished by various means. Some things we call fossils are actually almost identical to their status while alive, such as many fossil shells. Usually fossilification is a process where certain minerals replace the fossil's original material. A good example is petrified wood. The wood is replaced, cell by cell, with minerals which may be silicon and other minerals, to give the petrified wood the beautiful colors which it often has. It may also become opalized. Some fossilification is by drying, such as mummified things in desert areas. Some fossilization is done in regions which are anaerobic, which means there is no oxygen to aid in the deterioration of the item. Some fossils are entombed in amber and remain essentially just as they were before being trapped and entombed. Therefore fossil is a generic term for things which have been preserved for long periods of time, by many means.

The answer is, almost anywhere that there is a sedimentary formation. A sedimentary formation is a layer of the Earth's cover which accumulated over time. It may be dirt, mud, debris which may form shale, then slate in time; it may be shells and other calcereous (i.e. CaCO3 or calcium carbonate) living things or silicon, and other living things, which may form limestone and marble; or plants, trees other Plant Kingdom living things, to make peat and coal. These layers gradually build up by the action of wind, water, and other means. Most sedimentary formations are in horizontal layers (except where the action of the Earth's crust has thrust them upward or diagonally).

That is like asking how long is a piece of string. Fossilification can be fairly rapid or it may be hundreds of millions of years and still not be fully fossilized. A good example is when your PMNS Curator digs at Florissant, Colorado which is lower Oligocene fossils (approx. 35,000,000). While you find fossil leaves and insects, where the item is now a carbon residue, you can find pieces of wood in the same matrix which crumbles, but appears to still be pretty much wood. For more information on how to tell the age of formations, and hence fossils in those formations.
, please

You may want to read Terry Proctor's award-winning article "Showing your Age" which appeared in the "BackBenders Gazette" on how to tell the age of specimens. Go to, click on Master Index, then click on Articles and then on"Showing your Age". This and other award-winning articles are available on this web site on the Articles page.

For more on fossils, go to, click on Master Index, then click on Fossils.

Insect embedded in Amber
Age unknown
Item -02
Pleistocene: Stallion
Tooth(l); Fetal Mammoth
Tusk (center); Bivalve and
adductor muscle (right)
Leisey Shell Pit,
Ruskin, Florida
Item -03
Pleistocene Camel
Leg Bone
Leisey Shell Pit
Ruskin, Florida
Item -04
Southern Quahog
Pleistocene Bivalve
Leisey Shell
Pit, Ruskin Florida
Item #-05
Pleistocene Giant Land
Tortoise claws
(Geocelone crassiscutata)
Leisey Shell Pit,
Ruskin, Florida
Item -06
Pleistocene Conch Shell
Leisey Shell Pit,
Ruskin, Florida
Item -07
Pleistocene Turritellidae
shell on Conch shell
Leisey Shell Pit
Ruskin, Florida
Item #- -08
Four species Crinoids
Mississippian #1 Telesiocrinus;
#2 Macrocrinus mundules;
#3 Abrutocrinus; #4 unknown
Crawfordsville, Indiana
Item # -09
Dinosaur egg
Item # -10
Oreodont skull
Harrison, Nebraska
Item # -11
Titanothere astragulus
(toe bone)
Harrison, Nebraska
Item # -12
Pleistocene Horse
Beach, Texas
Item # -13
Otoliths (fish earbones)
Mid-Eocene-Brazos River
near Bryan, Texas
Item # -14
Venericardia densata
Mid-Eocene-Brazos River
near Bryan, Texas
Item # -15
Belosaepia veatchi
(Squid beak)
Mid-Eocene-Brazos River
near Bryan, Texas
Item # -16
Interior of a
Crinoid head
age unknown
Robert Cross Collection
Item # -17
Item # -18
age unknown
Robert Cross Collection
Item # -19

This site is still under construction. Thank you for your patience.
Copy below here is for use in adding other items which were on the previous website.

#1 Annularia radiata fossil leaves (Pennsylvanian era--310MYBP) from Tulsa County, Oklahoma (NEED TO FIND AND ADD PIX)

#2 Mastodon Tooth (Pleistocene era)--from Florida

#3 Eurypterid lacustrus (Sea Scorpion) (Silurian era) from New York

#4 Conus Shell (Middle Eocene era) from Burleson County, Texas

#5 Oreodont (Oligocene) a browsing animal about the size of a collie or sheep from Harrison, Nebraska

#6 Fossil Fern Plate #7 (Pennsylvanian era 310MYBP) from Tulsa County, Oklahoma (NEED TO FIND AND ADD PIX )

#7 Fossil Fern Plate #7 (Pennsylvanian era 310MYBP) from Tulsa County, Oklahoma

#8 Lepidodendron tree root (Pennsylvanian era--310MYBP) from Tulsa County, Oklahoma

This is the copy to the right hand side of the Page:
The PROCTOR MUSEUM OF NATURAL SCIENCE, of which I have been Curator for 15 years NOW has their website online.

The PMNS website is Please visit this site and you will be amazed at the amount of natural scientific material, including fossils, shells, insects, articles, biographies, places and trips and much more.

Trips are being planned on the PMNS website under "Places and Trips" and then click on "Upcoming Trips".

Fossil collecting & Paleontology have become more popular in recent years with the finding of more dinosaurs and Jurassic Park. Paleontologist Robert Bakker, PhD was a consultant on Jurassic Park.
Dr. Proctor had the privilege of digging dinosaurs with Dr. Bakker for a week in August, 1994. The dig was in the famous Como Bluff area of Wyoming. Dr. Proctor learned a great deal about getting dinosaur bones out of the ground from Dr. Bakker.
For the past 15 years Dr. Proctor has been Curator and Board Chairman of the Proctor Museum of Natural Science. He has also been Chairman of the Paleo Section of the Houston Gem & Mineral Society and was twice the Vice-President of HGMS and also Show Chairman.

Rockhounding is great and healthy exercise but more than that it gives one an immense sense of the enormity of God's creation. From the most simple life form to the the huge whales and dinosaurs, some form of life has existed on this planet for most of the 4,600,000,000 years since this planet was created.

Some folks like to hang Paleontological and Natural History type art work in their homes and office. Terry Woodbeck, CEO of the new Tulsa Spine Hospital chose the double-matted, beautifully framed, Eocene Conus Shell with the "contours" effect to hang in that new hospital when it opens. You may want to consider joining a "Rock Hound" Club in your area and get out in the fresh air and dig up some history yourself.

There is a larger picture of a Florissant, Colorado mosquito (which is stored)
Here is the copy:
Fossil Mosquito (early Oligocene 35MYBP) Florissant, Colorado