Late Eocene white pines (Pinus subgenus Strobus) from southern China

Area of Science:

• Paleobotany
• Plant Evolution
• Fossil Record Analysis

Background:

• The genus Pinus L. diversified into two subgenera by the Late Cretaceous.
• Subgenus Strobus (D. Don) Lemmon is less documented in East Asia compared to subgenus Pinus L.

Purpose of the Study:

• To describe a new fossil pine species, Pinus maomingensis sp. nov.
• To establish the first megafossil record of subgenus Strobus from southern China.

Main Methods:

• Morphological analysis of a compressed seed cone from the upper Eocene Maoming Basin.
• Examination of cone scale morphology, including terminal umbo, apophysis, and cuticle structure.
• Identification of associated needle leaves with deciduous sheaths.

Main Results:

• Pinus maomingensis sp. nov. is established, belonging to subgenus Strobus, section Quinquefoliae, subsection Strobus.
• Associated needle leaves confirm the presence of subgenus Strobus.
• This discovery represents the earliest megafossil evidence of subgenus Strobus in southern China.

Conclusions:

• Subgenus Strobus members were present in southern China by the Late Eocene.
• The Maoming Basin likely bordered a mountainous region during the Late Eocene, consistent with extant subgenus Strobus distributions.