From: Green River Formation, Uintah County Utah
Weight: 1.5 Ounces
Dimensions: 4 Inches Long, 2.3 Inches Wide (Plate)
Leaf Dimensions: 2.9 Inches Long & 0.5 Inches Wide
Item pictured is the one you will receive.
This is a genuine fossil, not a replica.
A rare twig bearing both leaves and fruits serves as a Rosetta stone, linking the vegetative and reproductive structures that formerly were only known from dispersed organs. Fruit and foliage characters distinguish Populus tidwellii sp. n. from Populus cinnamomoides (Lesquereux) MacGinitie (typified on specimens from Green River Station, WY), to which the isolated leaves had formerly been attributed. In addition, new data from fruits and foliage confirm that there were two distinct sympatric species of Populus in the Parachute Creek flora. These species, together with Pseudosalix and Salix, provide our earliest record of diverse Salicaceae. An interesting feature of P. tidwellii is that the inflorescence is terminal in contrast to extant species of Populus, in which the catkins are axillary and borne on the wood of the previous season. In addition, the infructescence shows lateral branching near its base, distinguishing it from the simple racemes of extant species of the genus.
Fossil representatives abundant in shales of the early Middle Eocene of the Green River Formation in Utah, Colorado, and Wyoming, and it is clear that the family was an important component of vegetation that surrounded the large lakes in which these shales were deposited.