Pre-Carpels from the Middle Triassic of Spain

Area of Science:

• Paleobotany
• Evolutionary Biology
• Plant Morphology

Background:

• Hypotheses on carpel evolution lack substantial fossil evidence.
• Early Jurassic angiosperm discoveries prompt investigation into Triassic precursors.
• The origin of angiosperm carpels remains a significant evolutionary question.

Purpose of the Study:

• To investigate the morphology of *Combina* gen. nov., a Middle Triassic fossil.
• To test hypotheses regarding carpel evolution using fossil evidence.
• To identify potential precursors of angiosperm carpels in Mesozoic flora.

Main Methods:

• Light microscopy and Scanning Electron Microscopy (SEM) were employed.
• Detailed observation of the reproductive structures of *Combina*.
• Comparative analysis with known Mesozoic gymnosperms and angiosperms.

Main Results:

• The lateral unit of *Combina* features an axillary anatropous ovule.
• A subtending bract almost completely encloses the ovule.
• This structure shows similarities to both Mesozoic conifers and early angiosperms.

Conclusions:

• *Combina* gen. nov. represents a chimeric fossil plant.
• It provides evidence supporting theoretical predictions of carpel evolution.
• This finding narrows the morphological gap between gymnosperms and angiosperms.