Palmoxylon


Palmoxylon is an extinct genus of palm named from petrified wood found around the world.

Fossil record

This genus is known in the fossil record from the Late Cretaceous to the Miocene. Fossils of species within this genus have been found in Germany, Italy, United States, Egypt, Libya and Argentina. Many species were described from the Deccan Traps in India.

Distribution

A number of species from the Cretaceous and Cenozoic have been described from the Patagonia region of South America. There have been a number of species reported from Egypt which are dated to the Late Eocene and Early Miocene.
Specimens from the Oligocene epoch can be collected from many scattered sites in east Texas and western Louisiana. Fossils found near fossil palmwood include corals, sponges, and mollusks, indicating that the palms grew along prehistoric beaches. For millions of years, the Gulf Coast shoreline has been moving farther south.
In Texas and Louisiana, petrified palmwood is most common in the Toledo [Bend Reservoir|Toledo Bend] area, which is shared by both states. It was left by trees that grew when the Gulf of Mexico's shoreline was much farther north from its present-day position. In Louisiana, petrified palmwood is found in the parishes of Rapides, Natchitoches, Grant, and Sabine.

Description

Petrified palmwood includes a group of fossil woods that contain prominent rod-like structures within the regular grain of the silicified wood. Depending upon the angle at which they are cut by fracture, these rod-like structures show up as spots, tapering rods, or continuous lines. The rod-like structures are sclerenchyma bundles that comprise part of the woody tissues that gave the wood its vertical strength.
Petrified palmwood is a favorite of rock collectors because it is replaced by silica and exhibits well-defined rod-like structures and variety of colors. As a result, it exhibits a wide range of colors and designs when cut that can be incorporated into jewelry and other ornamental items. Because it is composed of silica, it is hard enough to polish and withstand the wear and tear of normal use.

Archaeology

In Grant Parish, Louisiana, Native Americans used petrified palmwood to make projectile points and other tools such as knives, awls, and scrapers. Projectile points and other tools crafted from petrified palmwood have been discovered in central Grant Parish by H.R. Hicks and other Native American artifact collectors. It is the state stone of Texas and the official state fossil of Louisiana.

Species

There are more than 200 species assigned to the genus Palmoxylon at this time.
  • Palmoxylon araneus Nour-El-Deen, El-Saadawi & Thomas, 2018
  • Palmoxylon arcotense
  • Palmoxylon bhisiensis Dutta et al., 2007
  • Palmoxylon blandfordiSchenk, 1882
  • Palmoxylon bororense
  • Palmoxylon chhindwarense Prakash, 1960
  • Palmoxylon colei
  • Palmoxylon compactum
  • Palmoxylon concordiense
  • Palmoxylon contortum
  • Palmoxylon dakshinense Prakash, 1960
  • Palmoxylon deccanensis Sahni, 1964
  • Palmoxylon dilacunosum Ambwani, 1984
  • Palmoxylon edenense
  • Palmoxylon elsaadawii Nour-El-Deen, El-Saadawi & Thomas, 2018
  • Palmoxylon eocenum Prakash, 1962
  • Palmoxylon geometricum
  • Palmoxylon hislopi Rode, 1933
  • Palmoxylon indicum
  • Palmoxylon kamalamRode, 1933
  • Palmoxylon lametaei
  • Palmoxylon livistoniforme
  • Palmoxylon livistonoides Prakash & Ambwani, 1980
  • Palmoxylon macginitiei
  • Palmoxylon mathuri Sahni, 1931
  • Palmoxylon parapaniensis Lakhanpal et al., 1979
  • Palmoxylon parthasarathyi Rao & Menon, 1964
  • Palmoxylon patagonicum
  • Palmoxylon pichaihuensis Ottone, 2007
  • Palmoxylon pondicherriense
  • Palmoxylon pyriforme
  • Palmoxylon qatraniense Nour-El-Deen, El-Saadawi & Thomas, 2018
  • Palmoxylon queenslandicum
  • Palmoxylon rewahense
  • Palmoxylon riograndense
  • Palmoxylon rionegrense Ancibor, 1995
  • Palmoxylon sagari
  • Palmoxylon santarosense Ancibor, 1995
  • Palmoxylon superbum Trivedi & Verma, 1971
  • Palmoxylon trachycarpeaeense Kumar & Khan in Kumar, Spicer & Khan, 2025
  • Palmoxylon valchetense Ancibor, 1995
  • Palmoxylon vaterum
  • Palmoxylon wadai Sahni, 1931
  • ''Palmoxylon yuqueriense''