Enigmatic fossil plants with three-dimensional, arborescent-growth architecture from the earliest Carboniferous of New Brunswick, Canada.
Curr Biol
; 34(4): 781-792.e3, 2024 02 26.
Article
in En
| MEDLINE
| ID: mdl-38309270
ABSTRACT
The evolution of arborescence in Devonian plants, followed by their architectural radiation in the Carboniferous, is a transition fundamental to Earth-system processes and ecological development. However, this evolutionary transition in trees is based on preserved trunks, of which only a few known specimens possess crowns. We describe Mississippian-aged (Tournaisian) trees with a unique three-dimensional crown morphology from New Brunswick, Canada. The trees were preserved by earthquake-induced, catastrophic burial of lake-margin vegetation. The tree architecture consists of an unbranched, 16-cm-diameter trunk with compound leaves arranged in spirals of â¼13 and compressed into â¼14 cm of vertical trunk length. Compound leaves in the upper â¼0.75 m of the trunk measure >1.75 m in length and preserve alternately arranged secondary laterals beginning at 0.5 m from the trunk; the area below the trunk bears only persistent leaf bases. The principal specimen lacks either apical or basal sections, although an apex is preserved in another. Apically, the leaves become less relaxed toward horizontal and are borne straight at an acute angle at the crown. The compact leaf organization and leaf length created a crown volume of >20-30 m3. This growth strategy likely maximized light interception and reduced resource competition from groundcover. From their growth morphology, canopy size, and volume, we propose that these fossils represent the earliest evidence of arborescent subcanopy-tiering. Moreover, although systematically unresolved, this specimen shows that Early Carboniferous vegetation was more complex than realized, signaling that it was a time of experimental, possibly transitional and varied, growth architectures.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Plants
/
Fossils
Country/Region as subject:
America do norte
Language:
En
Journal:
Curr Biol
Journal subject:
BIOLOGIA
Year:
2024
Document type:
Article
Country of publication:
Reino Unido