Eutactoides wintonensis

Name

Eutactoides wintonensis

Rank

Species

Generic Name

[Genus] Eutactoides

Authors (Pub.)

Pole M. S.  

Publication

Mid-cretaceous conifers from the Eromanga Basin, Australia [2000/4]

Journal

Australian Systematic Botany

Volume

13

Issue

2

Page number

185

Year

2000

Fossil Status

foliage

Stratigraphy

Cenomanian

Strat. comment

Winton Formation

Location

GSQ (Geological Survey of Queensland) Eromanga-1 drill hole, Eromanga Basin, south-western Queensland, Australia

Paleoregion

Gondwana (Australia)

Data for Holotypus

Repository

University of Queensland, Brisbane, Australia

Repository Number

SL427 (ERO-37)

Num

23 E

Pub.

Mid-cretaceous conifers from the Eromanga Basin, Australia [2000/4]

Diagnosis

Shoot phyllotaxy unknown. Leaves scale-like, apex blunt, slightly recurved with ridge and central hole on adaxial side, ovate or tetragonal in cross-section with distinct edges and slight keels on adaxial and abaxial surfaces; base not decurrent, rising directly from shoot axis, possibly with abscission zone; length 2.0–3.0 mm, width 2.0 mm; single-veined. Amphistomatic (single broad zone on one leaf surface, two zones separated by a narrow, nonstomatal zone on other). Stomates not in clear, discrete rows (but some linear trends apparent), widely separated (but some scattered overlapping stomates), extending from apex to base, in short, loose chains, about 20 rows on a surface, parallel to long axis in flattened leaf-form, but diverging from central stomatal free zone in non-flattened leaf form (producing a ‘herring-bone’ pattern), oriented obliquely (mostly less than 30° from longitudinal); haplocheilic, dicyclic, encyclocytic, outline subcircular to irregular, cuticle over guard cells and inner portion of subsidiary cells thinner than over epidermal cells, polar extensions welldeveloped, edge of stomatal pore flush with rest of surface, cuticle over subsidiary cells and guard cells clearly visible in stomatal pit. Epidermal cells in files, ornamentation smooth, typically isodiametric (L/W ration rarely over 4.0, never over 5.0), polygonal, glabrous.