Petrified palmwood
Encyclopedia
Palmoxylon is an extinct genus of palm
Arecaceae
Arecaceae or Palmae , are a family of flowering plants, the only family in the monocot order Arecales. There are roughly 202 currently known genera with around 2600 species, most of which are restricted to tropical, subtropical, and warm temperate climates...

 named from petrified wood
Petrified wood
Petrified wood is the name given to a special type of fossilized remains of terrestrial vegetation. It is the result of a tree having turned completely into stone by the process of permineralization...

 found around the world. A number of species from the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 and Tertiary
Tertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...

 have been described from the Patagonia
Patagonia
Patagonia is a region located in Argentina and Chile, integrating the southernmost section of the Andes mountains to the southwest towards the Pacific ocean and from the east of the cordillera to the valleys it follows south through Colorado River towards Carmen de Patagones in the Atlantic Ocean...

 region of South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

. There have been a number of species reported from Egypt
Egypt
Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...

 which are dated to the Late Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...

 and Early Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...

.

Specimens from the Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...

 epoch (34 - 23 mya) can be collected from many scattered sites in east Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

 and western Louisiana
Louisiana
Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...

. Fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

s found near fossil palmwood include coral
Coral
Corals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...

s, sponge
Sea sponge
Sponges are animals of the phylum Porifera . Their bodies consist of jelly-like mesohyl sandwiched between two thin layers of cells. While all animals have unspecialized cells that can transform into specialized cells, sponges are unique in having some specialized cells, but can also have...

s, and mollusks, indicating that the palms grew along prehistoric beach
Beach
A beach is a geological landform along the shoreline of an ocean, sea, lake or river. It usually consists of loose particles which are often composed of rock, such as sand, gravel, shingle, pebbles or cobblestones...

es. For millions of years, the Gulf Coast shoreline has been moving farther south.

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
Rockhounding
Amateur geology is the recreational study and hobby of collecting rocks and mineral specimens from their natural environment.-Collecting:...

 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.

In Texas and Louisiana, petrified palmwood is most common in the Toledo Bend
Toledo Bend Reservoir
Toledo Bend Reservoir is a reservoir on the Sabine River between Texas and Louisiana. The lake has an area of 185,000 acres , the largest man-made body of water in Texas, the largest in the South, and the fifth largest in the United States. The dam is capable of generating 92 megawatts of...

 area, which is shared by both states. It was left by trees that grew when the Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...

'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. In Grant Parish (and probably in other areas also), 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
State fossil
Most American states have made a state fossil designation, in many cases during the 1980s. It is common to designate one species in which fossilization has occurred, rather than a single specimen, or a category of fossils not limited to a single species....

 of Louisiana.

Species

There are more than 200 species assigned to the genus Palmoxylon at this time.
  • Palmoxylon arcotense
  • Palmoxylon bhisiensis Dutta et al., 2007 (Cretaceous; Deccan Traps
    Deccan Traps
    The Deccan Traps are a large igneous province located on the Deccan Plateau of west-central India and one of the largest volcanic features on Earth. They consist of multiple layers of solidified flood basalt that together are more than thick and cover an area of and a volume of...

    , India)
  • Palmoxylon blandfordiSchenk, 1882 (Cretaceous; Deccan Traps, India)
  • Palmoxylon bororense
  • Palmoxylon chhindwarense Prakash, 1960 (Cretaceous; Deccan Traps, India)
  • Palmoxylon colei (Eocene; Green River Formation
    Green River Formation
    The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes. The sediments are deposited in very fine layers, a dark layer during the growing season and a light-hue inorganic layer in winter. Each pair of layers is called a varve and...

    , Eden Valley, Wyoming)
  • Palmoxylon compactum
  • Palmoxylon concordiense
  • Palmoxylon contortum (Eocene; Green River Formation
    Green River Formation
    The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes. The sediments are deposited in very fine layers, a dark layer during the growing season and a light-hue inorganic layer in winter. Each pair of layers is called a varve and...

    , Eden Valley, Wyoming)
  • Palmoxylon dakshinense Prakash, 1960 (Cretaceous; Deccan Traps, India)
  • Palmoxylon deccanensis Sahni, 1964 (Cretaceous; Deccan Traps, India)
  • Palmoxylon dilacunosum Ambwani, 1984
  • Palmoxylon edenense (Eocene; Green River Formation
    Green River Formation
    The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes. The sediments are deposited in very fine layers, a dark layer during the growing season and a light-hue inorganic layer in winter. Each pair of layers is called a varve and...

    , Eden Valley, Wyoming)
  • Palmoxylon eocenum Prakash, 1962 (Cretaceous; Deccan Traps, India)
  • Palmoxylon geometricum
  • Palmoxylon hislopi Rode, 1933 (Cretaceous, Deccan Traps; India)
  • Palmoxylon indicum
  • Palmoxylon kamalamRode, 1933 (Cretaceous, Deccan Traps; India)
  • Palmoxylon lametaei Dutta
    Debi Dutta
    Debi Dutta is a model and actress. She has appeared in commercials of Pepsi, Nokia, HCL Laptops, Close Up. She entered into movies by playing character of Aparna, a childhood friend of Ranbir Kapoor in the movie Rocket Singh: Salesman of the Year ....

    , Ambwani, and Estrada-Ruiz
    (Maastrichtian
    Maastrichtian
    The Maastrichtian is, in the ICS' geologic timescale, the latest age or upper stage of the Late Cretaceous epoch or Upper Cretaceous series, the Cretaceous period or system, and of the Mesozoic era or erathem. It spanned from 70.6 ± 0.6 Ma to 65.5 ± 0.3 Ma...

    ; Lameta Formation
    Lameta Formation
    The Lameta Formation is a sedimentary rock formation found in Madhya Pradesh, Gujarat, and Maharashtra, India. It is of Maastrichtian age , and is notable for its dinosaur fossils...

    , Deccan Traps, India)
  • Palmoxylon livistoniforme
  • Palmoxylon livistonoides Prakash & Ambwani, 1980 (Cretaceous, Deccan Traps; India)
  • Palmoxylon macginitiei (Eocene; Green River Formation
    Green River Formation
    The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes. The sediments are deposited in very fine layers, a dark layer during the growing season and a light-hue inorganic layer in winter. Each pair of layers is called a varve and...

    , Eden Valley, Wyoming)
  • Palmoxylon mathuri Sahni, 1931 (Cretaceous, Gujarat, India)
  • Palmoxylon parapaniensis Lakhanpal et al., 1979 (Cretaceous, Deccan Traps; India)
  • Palmoxylon parthasarathyi Rao & Menon, 1964 (Cretaceous, Deccan Traps; India)
  • Palmoxylon pichaihuensis
  • Palmoxylon pondicherriense
  • Palmoxylon pyriforme
  • Palmoxylon queenslandicum
  • Palmoxylon rewahense
  • Palmoxylon riograndense
  • Palmoxylon sagari
  • Palmoxylon santarosense
  • Palmoxylon superbum Trivedi & Verma, 1971 (Cretaceous, Deccan Traps; India)
  • Palmoxylon valchetense
  • Palmoxylon vaterum
  • Palmoxylon wadai Sahni, 1931 (Cretaceous; Deccan Traps, India)
  • Palmoxylon yuqueriense

External links

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