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What Kind Of Wood?


ashcraft

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This is a picture of a cross section of a piece of wood, probably Cretaceous. I had assumed it was palm wood, but a museum curator looked at the photo and said it didn't look like any palm wood he had ever seen. I do not have a macro lens, and in order to generate this image I used a setup at the university they used to copy books with. I took a picture at auto focus, then adjusted it a fraction of a turn, then took another, etc. until I had generated about 200 images, and finally found one in good enough focus to expand the photo to about the limits the pixels would allow. Has anybody ever seen anything like this? Any gneral comments?

Brent Ashcraft

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ashcraft, brent allen

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Hi Brent,

I was curious about this specimen as well. Thanks for the grand effort to capture it making 200 microscopic images and going through all of them to find the best one to show us. The least I could do was forward it to one of top experts of petrified wood. Although not conclusive to exact taxon, at a minimum headed in the right direction perhaps?

Thanks again for posting and hope this info is useful:

"Looks like a tropical hardwood. I don’t know much about tropical hardwoods. Most of them look the same. Diffuse porous with indistinct growth rings – multiple pores. I do not deal with them in my book. There are thousands of species, literally. I suspect this wood is more modern than Cretaceous."

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Hi Brent,

I was curious about this specimen as well. Thanks for the grand effort to capture it making 200 microscopic images and going through all of them to find the best one to show us. The least I could do was forward it to one of top experts of petrified wood. Although not conclusive to exact taxon, at a minimum headed in the right direction perhaps?

Thanks again for posting and hope this info is useful:

"Looks like a tropical hardwood. I don’t know much about tropical hardwoods. Most of them look the same. Diffuse porous with indistinct growth rings – multiple pores. I do not deal with them in my book. There are thousands of species, literally. I suspect this wood is more modern than Cretaceous."

Thanks for the input, to both you and your friend. Puzzling to me (and I am not expecting answers), but most of the wood from this area shows distinct growth rings. It is most assuredly cretaceous, probably from the McNairy sandstone, which is very late Matraschitan (sp?), up to the point of Chix impact. Attached is another example of wood from this area showing the distinct growth rings, and what I assume are also oil cells.

I always assumed that the growth rings were the result of a wet/dry season, as leaf fossils indicate that this was a very tropical enviornment at the time.

Brent Ashcraft

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ashcraft, brent allen

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Excellent pictures, Brent. The first one is probably Elm. The second one is Oak.

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Thanks all, if the first one is elm, I now know why you never try to split it with a maul. The website also looks very interesting, but I am going to have to learn alot to use it, which is a good thing.

Brent Ashcraft

ashcraft, brent allen

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I should have also mentioned that this is the level of detail required to identify a lot of petrified wood. Especially when trying to pin down the exact species (which I cannot do).

Oak and palm can usually be identified without magnification. Oak has unusually strong rays and palm is pretty obvious by the structure of the "straws".

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I looked on the previously mentioned website at some photos of oak (Quercus), and they do look similar enough to say that in my opinion that it is an oak. So I looked on a taxa a lady recently did on this area at the cretaceous/cenozoic boundary. In the list she notes "Quercoidites", which I assume is related to oak? I cannot reference the name anywhere, and I can't find an evolutionary history of oaks.

Can anybody help me?

Brent Ashcraft

ashcraft, brent allen

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Quercoidites sounds like a form taxon.

"There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant

“Try to learn something about everything and everything about something.” - Thomas Henry Huxley

>Paleontology is an evolving science.

>May your wonders never cease!

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Modern species of Quercus range from the tropics to temperate areas and have simple leaves with pinnate venation and cupulate fruits. The unisexual inflorescences have staminate florets with a lobed perianth and four to nine stamens. Pollen is tricolporate and the fruit is an acorn. The earliest fossils of Quercus are found in the Oligocene (Crepet, 1989). Staminate inflorescences of Q.oligocenensis from the Oligocene Catahoula Formation consist of sessile florets, each with a slightly lobed perianth and six stamens (Daghlian and Crepet, 1983). Leaves are ~3cm long with two to four lobes on each. Permineralized acorns are known from the Miocene.

Paraquercinium is a Cretaceous wood that shares many anatomical features with extant Quercus and Lithocarpus (Wheeler et al., 1987). The wood has rays of two sizes and indistinct growth rings. Pores on the vessels are solitary and perforation plates are simple. Quercinium is another fagaceous wood reported from the Eocene of Yellowstone National Park (Wheeler et al., 1987). The wood is a semi-ring porous. In Quercinium lamarense, growth rings are 2-10mm wide and apotracheal parenchyma occurs in distinct bands one cell wide (Wheeler et al., 1987). Permineralized Cenozoic wood that is structurally similar, or even identical, to modern Quercus wood has been assigned to the genus Quercoxylon (Selmeier, 1992b).

RE: Paleobotany: The Biology and Evolution of Fossil Plants - Academic Press

2009 Second Edition by Thomas N. Taylor, Edith L. Taylor, Michael Krings et al.

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I am getting befuzzled now. The lady who did the taxonomic list was working with pollen. She was definitely in the Cretaceous and earliest Paleocene (McNairy, Owl Creek, and Clayton). She assigned some of the pollen to Quercoidites sp., which I assume is an oak or oak like relative, in both the end Cretaceous (Mastrachian sp?), and the very earliest Paleocene. Her conclusion is that the bottom part of the Clayton is actually tsunami wash, and her arguments are very convincing.

The petrified wood that I find is in float in the bottom of local creeks, some of it can be quite large, measured in feet. The main component of the float is sandstone, and it appears to my eye to be McNairy. We do not have any deposits past the earliest Eocene, which is the Porter's Creek clay (kitty litter), which is very distinctive, and not in the creeks. We also have the Mounds Gravel, which is thought to be Pleiocene, and is also very distinctive and not present. The only other possibility is Holly Springs group, which appears a little further south and east which is equivalent to the Fort Union formation, also paleocene, or eocene (in Missouri anyway-don't get me started)

I guess it boils down to this, if it is oak or oak related, could it be coming out of the Cretaceous deposits?

Brent Ashcraft

ashcraft, brent allen

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Oaks definitely existed in the Cretaceous.

In reading the pollen paper, did you get the impression that Quercoidites might be a polled form-genus, referred to oaks?

"There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant

“Try to learn something about everything and everything about something.” - Thomas Henry Huxley

>Paleontology is an evolving science.

>May your wonders never cease!

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Oaks definitely existed in the Cretaceous.

In reading the pollen paper, did you get the impression that Quercoidites might be a polled form-genus, referred to oaks?

Read? What a concept, I feel like one of my students. After reading, she does imply that Quercoidites is closely linked to modern Quercus. Also, I was mistaken in saying she had found oak pollen in Owl Creek (end Cretaceous), she found it in the Clayton, which is first Paleocene, and became more and more common in the deposits as they became more modern.

I found the wood about 30 miles "upstream" from whre she had been sampling, which could have had different enviornmental conditions, so maybe not so unexpected, then as the embayment transgressed southward, oaks became more common.

Maybe

Brent Ashcraft

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I sent the pics off to my local pet wood expert and he says legume instead of elm, but cannot go down to the species level from the picture. He agrees with the oak ID.

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I stumbled across this database last night. It looks like there's over 30K images of modern and fossil wood.

http://insidewood.li...su.edu/search.1

great wood and pictures, very useful link also, thanks!:)

"Your serpent of Egypt is bred now of your mud by the operation of your sun; so is your crocodile." Lepidus

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