Hughmillerites vancouverensis sp. nov. and the Cretaceous diversification of Cupressaceae.
Am J Bot
; 101(12): 2136-47, 2014 Dec.
Article
in En
| MEDLINE
| ID: mdl-25480710
ABSTRACT
UNLABELLED ⢠PREMISE OF THE STUDY Two ovulate conifer cones, one of which is attached terminally to a short leafy shoot, reveal the presence of a new species of Hughmillerites in the Early Cretaceous Apple Bay flora of Vancouver Island, British Columbia, Canada. This ancient conifer expands the diversity of Cupressaceae in the Mesozoic and reveals details about the evolution of Subfamily Cunninghamioideae.⢠METHODS:
Specimens were studied from anatomical sections prepared using the cellulose acetate peel technique.⢠KEYRESULTS:
Vegetative shoots have helically arranged leaves that are Cunninghamia-like. Seed cones have many helically arranged bract/scale complexes in which the bract is larger than the ovuliferous scale. Each ovuliferous scale has three free tips that separate from the bract immediately distal to an inverted seed. Several ovuliferous scales show interseminal ridges between seeds.â¢CONCLUSIONS:
This study documents a new extinct species of cunninghamioid conifers, Hughmillerites vancouverensis, expanding the record of the genus from the Late Jurassic to the Early Cretaceous. This new extinct species emphasizes the important role that conifers from subfamily Cunninghamioideae played in the initial evolutionary radiation of Cupressaceae. In light of recent findings in conifer regulatory genetics, we use H. vancouverensis to hypothesize that variations of expression in certain gene homologues played an important role in the evolution of the cupressaceous ovuliferous scale.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Phylogeny
/
Seeds
/
Cupressaceae
/
Plant Components, Aerial
/
Biological Evolution
/
Ovule
/
Fossils
Country/Region as subject:
America do norte
Language:
En
Journal:
Am J Bot
Year:
2014
Document type:
Article