Guest Blogger Victor Gordillo

The fossilization of organisms is quite an incredible process and only occurs during exceptionally rare occasions—just as in the case of this tiny cone (Figure 1). When the conditions were perfect some 67 million years ago, this small, delicate part of a giant prehistoric tree became a part of the fossil record ("Science Olympiad: Virtual”). This prehistoric cone comes from the Metasequoia or dawn red wood tree and is one of the oldest species of seed-bearing plants.



 

Figure 1. A 67 million-year-old petrified Sequoia dakotensis cone from the Hell Creek Formation. The matrix covering this delicate fossil has been carefully removed. S.W. Veatch specimen, photo by S. W. Veatch, Oct 2011.

The scientific name of this fossil cone is Sequoia dakotensis. The cone goes back to the Cretaceous period. Although the genus is extant (still in existence), the species is extinct (Bluemle, 2007). This particular specimen was found in the Hell Creek Formation in North Dakota, a heavily studied formation containing a variety of upper Cretaceous organisms; the Hell Creek Formation is primarily in Montana and stretches into portions of North and South Dakota and into parts of Wyoming ("The virtual fossil”). The fossil cone depicted in Figure 1 is approximately one centimeter across and is three grams in mass.

This tiny cone dropped to the ground one day long ago in the Cretaceous Period and likely rolled into a depression of some sort and remained there just a short time. This cone was then buried under sediment from an event that caused mud and sand to be washed into a depression that permitted rapid covering and burial of the cone. Over eons of time, water— infused with minerals, especially silica— penetrated the cone and slowly began to replace the organic matter of the cone with these minerals (Hamilton C & R.).

Taxonomy
Domain: Eukaryota
Kingdom: Plantae
Subkingdom: Viridaeplantae
Phylum: Tracheophyta
Subphylum: Euphyllophytina
Infraphylum: Radiatopses
Class: Pinopsida
Order: Pinales
Family: Cupcressaceae
Genus: Sequoia
Species: dakotensis
Botanical Name: Sequoia dakotensis

Although today North Dakota's ancient Cretaceous forests are long gone, they have left behind amazing badlands and stunning landscapes containing petrified tree trunks and fossil cones.

References Cited:

Bluemle , J. (2007, July 27). North Dakota's Petrified Wood. Retrieved from   https://www.dmr.nd.gov/ndgs/ndnotes/ndn3_h.htm

Hamilton, C., & R., n.d.). Science Views: The Formation of Fossils. Retrieved from http://www.scienceviews.com/dinosaurs/fossilformation.html

Science Olympiad: Virtual petrified wood museum. (n.d.). Retrieved from http://petrifiedwoodmuseum.org/soconiferophyta.htm

The virtual fossil museum. (n.d.). Retrieved from http://
www.fossilmuseum.net/Fossil_Sites/hellcreek.htm