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Lamanonia borealis
Lamanonia borealis L.J. Hickey Mem. Geol. Soc. Amer., 150: 129. 19 Jul 1977
- Name
- Lamanonia borealis
- Rank
- Species
- Generic Name
- [Genus] Lamanonia
- Authors (Pub.)
- Hickey L. J.
- Publication
- Stratigraphy and paleobotany of the Golden Valley Formation (Early Tertiary) of Western North Dakota [1977/7]
- Journal
- Memoirs of the Geological Society of America
- Volume
- 150
- Page number
- 129
- Year
- 1977
- Fossil Status
- leaves
- Stratigraphy
- Thanetian
- Location
- White Butte, Stark County, North Dakota, USA
- Paleoregion
- America (North)
Data for Holotypus
- Repository
- National Museum of Natural History, Smithsonian Institution, Washington, USA
- Repository Number
- USNM 43026
Data for Paratypus
- Repository
- National Museum of Natural History, Smithsonian Institution, Washington, USA
- Repository Number
- PU 20029, 20024 [pl. 30: 1]; USNM 43039 [pl. 29: 4], 43023, 43022; PU 20026, 20025; USNM 43024, 43042 [pl. 29: 2]; PU 20027, 20043; USNM 43025, USNM 43021, 43027, 43028A and B; PU 20028; USNM 43029; PU 20030, PU 20032 [pl. 30: 4], 20033 [pl. 29: 1], USNM 43034, 43033; PU 20035, 20036, 20037, USNM 43030, USNM 43031, 43038, PU 20040; USNM 43041.
- Diagnosis
- Leaflets symmetrical to slightly asymmetrical, especially at the base; straight
to falcate, l / w ratio highly variable, yet forming a complete sequence between the extremes of 2.6 and 10.2; I from 4.5 to 19.2 cm; w from 1 to 5.5 cm; apex attenuate; base acute to cuneate; leaflet substance thickened,
and margin rounded to truncate at the very base of the blade where it joints the petiolule, rarely the blade completely decurrent; form narrow ovate to ovate-lanceolate, less commonly very narrow elliptic to elliptic; margin serrate, serrations mostly acuminate-acuminate (type D-4), occasionally types A-4 and B-4, rarely margin appears dentate to entire, probably
resulting from imperfect preservation; leaflet texture chartaceous to coriaceous. Venation pinnate, semicraspedodromous, midvein straight or slightly curved, stout. Number of secondaries variable, average between 16 and 24 with extremes at 14 and 44, angle of divergence from 50° to 85°, average between 65° and 80°; the angle fairly uniform throughout a given
leaf; thickness of secondaries intermediate between the primary and the tertiaries; intersecondaries rare, parallel or subparallel to the secondaries; course of the secondaries gently and uniformly curved or abruptly upcurved at the margin; secondaries branching just before reaching the margin, sending one branch to the tooth or sinus and a generally weaker branch
along the margin to the ramifications of the superadjacent secondary; admedially from the outer fork of the secondaries there frequently arises a branch running to the superadjacent secondary and joining it at an acute angle; this inner camptodromous branch is especially prominent toward the leaflet apex and base, and in young leaves. Tertiary veins originating
from both sides of the secondaries mostly at right angles, occasionally acute on the outer side; emerging from the midrib at a right angle; thickness moderate to fine, all of equal thickness; course, retroflexed, recurved near the midrib. Quaternary veins thin, noticeably thinner than the tertiaries; quinternary veins thin and clearly distinct from the quaternaries; highest order of venation, fifth; highest order showing excurrent branching, fourth; marginal behavior of higher order venation, incomplete. Areolation of equant, polygonal meshes, moderately irregular in shape and of variable size, mostly less than 0.3 mm in diameter; no positively observed freely ending veinlets.
