Rock Identifier
Tyrannosaurus Rex Fossil Skull (Tyrannosaurus rex) — fossil
fossil

Tyrannosaurus Rex Fossil Skull

Tyrannosaurus rex

AI-generated identification · may be incorrect

Hardness varies by mineral replacement (Mohs 4-5 typically); bone structure composed of fossilized calcium phosphate and substituted minerals like silica; earthy to vitreous luster; heavy specific gravity.

Identified More fossil →
Explore Tyrannosaurus Rex Fossil Skull in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App StoreGoogle Play

Physical properties

Hardness varies by mineral replacement (Mohs 4-5 typically); bone structure composed of fossilized calcium phosphate and substituted minerals like silica; earthy to vitreous luster; heavy specific gravity.

Formation & geological history

Formed through permineralization where groundwater minerals replace organic bone material over millions of years, dating to the late Cretaceous period approximately 68 to 66 million years ago.

Uses & applications

Valuable for scientific research, museum exhibitions, and high-end private paleontology collections.

Geological facts

T. rex had one of the strongest bite forces of any terrestrial animal, capable of crushing bone. Complete skulls are exceptionally rare and scientifically priceless.

Field identification & locations

Identified by massive, banana-shaped teeth, robust facial bones, and large fenestrae in the skull; found primarily in North American rock formations like the Hell Creek Formation.

More like this

Other fossil specimens

Probable fossil-bearing rock or mineral concretion (Unidentified carbonate-rich concretion with a possible fossil inclusion) — fossil

Probable fossil-bearing rock or mineral concretion

Unidentified carbonate-rich concretion with a possible fossil inclusion

fossil
Likely fossil oyster shell (Fossilized bivalve shell; exact species cannot be identified from the image) — fossil

Likely fossil oyster shell

Fossilized bivalve shell; exact species cannot be identified from the image

fossil
Crinoid Stem Fossil in Matrix (Phylum Echinodermata, Class Crinoidea) — fossil

Crinoid Stem Fossil in Matrix

Phylum Echinodermata, Class Crinoidea

fossil
Fossiliferous limestone (likely a crinoidal or shell-fragment limestone) (Bioclastic limestone, composed chiefly of calcite (CaCO₃)) — sedimentary

Fossiliferous limestone (likely a crinoidal or shell-fragment limestone)

Bioclastic limestone, composed chiefly of calcite (CaCO₃)

sedimentary
Porous limestone pebble (Calcite-rich limestone (primarily CaCO₃); exact identification is uncertain from the image) — sedimentary

Porous limestone pebble

Calcite-rich limestone (primarily CaCO₃); exact identification is uncertain from the image

sedimentary
Fossil oyster shell (Oyster (family Ostreidae); shell composed chiefly of calcite (CaCO₃)) — fossil

Fossil oyster shell

Oyster (family Ostreidae); shell composed chiefly of calcite (CaCO₃)

fossil