Genre: Information/Explanation

N. spatulata has been identified from a single location in the Clarno Formation , the Clarno nut beds , type locality for both the formation and the species . The nut beds are approximately 3 kilometres ( 1 . 9 mi ) east of the unincorporated community of Clarno , Oregon , and considered to be middle Eocene in age , based on averaging zircon fission track radiometric dating which yielded an age of 43.6 and 43.7 ± 10 million years ago and Argon – argon dating radiometric dating which yielded a 36.38 ± 1.31 to 46.8 ± 3.36 mya date . The average of the dates resulted in an age range of 45 to 43 mya . The beds are composed of silica and calcium carbonate cemented tuffaceous sandstones , siltstones , and conglomerates which preserve either a lake delta environment , or alternatively periodic floods and volcanic mudflows preserved with hot spring activity . The species was described from a series of type specimens , the holotype specimen USNM 422378 , which was preserved in the paleobotanical collections of the National Museum of Natural History in Washington , D.C. and four paratype specimens . Two of the paratypes were also in the national Museum collections , while the remaining two were in the University of Florida collections in Gainsville , Florida . The fossils were part of a group of approximately 20,000 specimens collected from 1942 to 1989 by Thomas Bones , Alonzo W. Hancock , R. A. Scott , Steven R. Manchester , and a number of high school students . The N. spatulata specimens were first studied by graduate student R. A. Scott , who placed the species into the extinct genus Palaeonyssa as Palaeonyssa spatulata , with the 1954 type description of the species appearing in the journal Palaeontographica . Palaeonyssa was first described by Eleanor Reid and Marjorie Chandler from fossils preserved in the London Clay , with them describing several species in the genus . N. spatulata was re-examined by paleobotanist Steven R. Manchester of the University of Florida , who published a 1994 re-description for the species in the Journal Palaeontographica Americana . In the re-description Manchester noted there was very little difference between the extinct genus Palaeonyssa and the modern Nyssa , and deemed the two to be the same genus . The merging resulted in the recombination of Palaeonyssa spatulata as Nyssa spatulata . The fruits of N. spatulata have a generally rounded triangular to round endocarp in cross-section and are trilocular , similar to the extant N. talamancana . The outline of the endocarps is oblong to ellipsoid , having both apex and base rounded and showing 9 ridges running the length of the endocarp from base to apex . The fruits have an average length of 24 mm ( 0 . 94 in ) though lengths of 30 mm ( 1 . 2 in ) are seen . Similarly while the average girth of the fruits is 14.6 mm ( 0 . 57 in ) , thicker fruits reaching 21.5 mm ( 0 . 85 in ) are known . Each of the three locules has a slit like opening along the upper half of the endocarp , and are separated from each other by a wall of swirling groups of fibers . There is one seed per locule , with the locule having a c-shaped cross section , the chamber opening near the apex and narrowing near the base .