petrifiedwood01
Callixylon whiteanum, Progymnosperm trunk
1 of 15
petrifiedwood02
Diaphorodendron scleroticum, Lycopsid stems
2 of 15
petrifiedwood03
Psaronius brasiliensis, Tree fern trunk
3 of 15
petrifiedwood04
Palaeosmunda playfordi, Tree fern apex
4 of 15
petrifiedwood05
Rhexoxylon africanum, Corystosperm trunk
5 of 15
petrifiedwood06
Araucarioxylon arizonicum, Conifer trunk
6 of 15
petrifiedwood07
Araucaria mirabilis, Conifer cone
7 of 15
petrifiedwood08
Pararaucaria patagonica, Conifer cone
8 of 15
petrifiedwood09
Agathis sp., Conifer stem
9 of 15
petrifiedwood10
Nypa burtini, Palm nut
10 of 15
petrifiedwood11
Palaeophytocrene foveolata, Icacina vine fruit stone
11 of 15
petrifiedwood12
Coryloides hancocki, Hazel nut
12 of 15
petrifiedwood13
Ensete oregonense, Banana seed
13 of 15
petrifiedwood14
Iodicarpa ampla, Icacina vine fruit stone
14 of 15
petrifiedwood15
Quercus sp., Oak wood
15 of 15

View the entire gallery or click on the above images to enlarge.

Fossil plants preserved in detail by mineral infiltration are especially valued by paleobotanists because they preserve details of uncompacted form and cellular detail not found in plant impressions and compressions. The most informative kind of fossil is permineralization, in which the minerals fill cell cavities and conserve the original cell walls of the plant. Less useful are remains that are petrified, literally turned into stone, because even the cell walls are replaced by mineral. In Oregon, permineralized and petrified wood is generally preserved by silica derived from the alteration of volcanic rocks. In Ohio through Iowa another form of permineralized plant is found within coal seams, preserved by calcite in nodules colloquially called "coal balls". In black shales, plant material is permineralized by pyrite, again with preservation of microscopic details. These specimens were collected by Professor Retallack during his career as a paleobotanist. Photography by Win McLaughlin, text by Greg Retallack, and web development by Keith Hamm. Images © UO Museum of Natural and Cultural History. Production of this gallery was generously supported by The Ford Family Foundation.