Dating the origin of the Orchidaceae from a fossil orchid with its pollinator

Abstract

Since the time of Darwin, evolutionary biologists have been fascinated by the spectacular adaptations to insect pollination exhibited by orchids. However, despite being the most diverse plant family on Earth, the Orchidaceae lack a definitive fossil record and thus many aspects of their evolutionary history remain obscure. Here we report an exquisitely preserved orchid pollinarium (of Meliorchis caribea gen. et sp. nov.) attached to the mesoscutellum of an extinct stingless bee, Proplebeia dominicana, recovered from Miocene amber in the Dominican Republic, that is 15-20 million years (Myr) old. This discovery constitutes both the first unambiguous fossil of Orchidaceae and an unprecedented direct fossil observation of a plant-pollinator interaction. By applying cladistic methods to a morphological character matrix, we resolve the phylogenetic position of M. caribea within the extant subtribe Goodyerinae (subfamily Orchidoideae). We use the ages of other fossil monocots and M. caribea to calibrate a molecular phylogenetic tree of the Orchidaceae. Our results indicate that the most recent common ancestor of extant orchids lived in the Late Cretaceous (76-84 Myr ago), and also suggest that the dramatic radiation of orchids began shortly after the mass extinctions at the K/T boundary. These results further support the hypothesis of an ancient origin for Orchidaceae.

A Name by Any Other Tree

“…The first representatives of the cat family Felidae probably lived about 30 million years ago (McKenna and Bell 1997), while the common ancestor of modern orchids lived around 80 million years ago (Ramírez et al 2007). & They have different levels of diversity.…”

Visitação de orquídea por Melipona capixaba Moure & Camargo (Hymenoptera: Apidae), abelha ameaçada de extinção

“…Em um recente achado fóssil na República Dominicana, observou-se um polinário de orquídea (Meliorchis caribea) perfeitamente preservado, fi xo ao escutelo de uma extinta abelha sem ferrão (Proplebeia dominicana) recuperado de âmbar do Mioceno datado entre 15-20 milhões de anos (Ramírez et al 2007). A relação mais comumente observada entre abelhas e orquídeas envolve a tribo Euglossini, popularmente conhecida como abelhas das orquídeas.…”

The Ability of Spontaneous Autogamy in Four Orchid Species: Cephalanthera Rubra, Neottia Ovata, Gymnadenia Conopsea, and Platanthera Bifolia

“…Orchidaceae represents an interesting plant group, in which a dramatic radiation began after the mass extinction event at the Cretaceous/Tertiary boundary (Ramírez et al, 2007). At least 19,500 orchid species have been classified (Peakall, 2007), which distinguishes this family as one of the largest among angiosperms.…”