Meliorchis caribea
| Meliorchis caribea | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Temporal occurrence | ||||||||||||
| 20 to 15 million years | ||||||||||||
| Locations | ||||||||||||
|
Dominican Republic |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Meliorchis | ||||||||||||
| SRRamirez, Gravend., RBSinger, CRMarshall, NEPierce | ||||||||||||
| Scientific name | ||||||||||||
| Meliorchis caribea | ||||||||||||
| SRRamirez , Gravend. , RBSinger , CRMarshall , NEPierce |
Meliorchis is a fossil plant from the family of orchids (Orchidaceae). Only one find of her is known, namely a pollinarium that was enclosed in amber on a bee.
The pollinarium consists of two club-shaped pollinia, each of which is divided into over 100 pollen packages (massulae). Each of these packages consists of glued together pollen tetrads. The entire pollinium measures around 1000 × 500 µm, the individual pollen packets around 200 × 100 µm, a tetrad measures 20 × 20 µm.
The details of the pollinia suggest a relationship between the fossil orchid and the subtribe Goodyerinae . Similarly structured pollinia can be found in Kreodanthus and Microchilus . While in representatives of this group living today the pollinia are mostly attached to the head or the mouthparts of the pollinator, the pollinia of Meliorchis caribea are attached to the back, the mesoscutellum , of a bee of the species Proplebeia dominicana . In order for the pollinium to get there, the bee must have crawled into the orchid flower, under the column and thus under the stamen . The flower of Meliorchis caribea should therefore have had a large, curved column in relation to today's relatives.
The age of the fossil orchid is estimated to be 15 to 20 million years after the age of the Dominican amber . It is the oldest fossil that can be assigned to the orchid family without any doubt. The fossil was used by the discoverers to estimate the age of the entire family with it as a benchmark.
The genus name Meliorchis refers to the Meliponini , the scientific name of the stingless bees, which includes the Meliorchis pollinator . The species name caribea refers to the place where it was found in the Caribbean.
supporting documents
- Santiago R. Ramírez, Barbara Gravendeel, Rodrigo B. Singer, Charles R. Marshall & Naomi E. Pierce : Dating the origin of the Orchidaceae from a fossil orchid with its pollinator . In: Nature . tape 448 , 2007, p. 1042-1045 , doi : 10.1038 / nature06039 .