Paraphyllanthoxylon marylandense

Name

Paraphyllanthoxylon marylandense

Rank

Species

Generic Name

[Genus] Paraphyllanthoxylon

Authors (Pub.)

Herendeen P. S.  

Publication

Lauraceous wood from the mid-Cretaceous Potomac group of eastern North America: Paraphyllanthoxylon marylandense sp. nov. [1991/9]

Journal

Review of Palaeobotany and Palynology

Volume

69

Issue

4

Page number

278

Year

1991

Fossil Status

stems (wood)

Stratigraphy

Cenomanian

Strat. comment

Potomac Formation

Location

Mauldin Mountain, northeastern Maryland, U.S.A.

Paleoregion

America (North)

Data for Holotypus

Repository

Field Museum, Chicago, USA

Repository Number

PP35023

Num

Plate I, 1, 2; Plate II, 5, 7; Plate III, 2, 3

Pub.

Lauraceous wood from the mid-Cretaceous Potomac group of eastern North America: Paraphyllanthoxylon marylandense sp. nov. [1991/9]

Data for Paratypus

Repository

Field Museum, Chicago, USA

Repository Number

PP43591, PP43592, PP43617, PP43619, PP43620, PP43621, PP43622, PP43624, PP43625, PP43627, PP43629, PP43630, PP43631, PP43632, PP43636

Diagnosis

Mature wood: growth rings absent; vessels solitary and in radial multiples of 2 5, generally 2-3; tangential diameter 55-1141~m (X=81 lam, n=36); outline of solitary vessels circular to oval in transverse section; vessel walls thin, fine spiral thickenings occasionally present; vessel density 35-60 per mm 2 (n=3); thin walled tyloses common; vessel element length 310-5901am (X= 423 lain, n=15); perforation plates simple, end walls oblique; intervascular pits crowded, alternate, 3-9 lain across, hexagonal pattern sometimes present; vessel-ray parenchyma pits variable, not like intervascular pits, round to elongate, apertures large, borders narrow. Rays heterocellular, 1-4 seriate, 2-3 seriate most common; number of uniseriate marginal rows of multiseriate rays variable, 1-7, commonly 1-3; vertical fusions common; ray height 220-1040 ~m. Imperforate tracheary elements septate, pits small, unbordered; outline in transverse section round to polygonal. First formed secondary xylem: Vessels predominantly solitary; perforation plates variable, simple to compound with 1-3 bars; lateral pitting variable, round, elliptical, to scalariform, bordered; vessel member length unclear; helical thickenings prominent in earliest wood, becoming less well developed with increasing distance from pith; tyloses present in larger vessels. Imperforate tracheary elements with large bordered pits occasional in early wood. Rays composed of upright cells in early wood, becoming progressively more heterocellular in older wood. Pith diameter 0.5 x 1.0 ram, consisting of isodiametric cells. A transition to vessel and ray structures of more mature wood occurs within 1 mm of the pith.