''Roystonea palaea'' is an extinct species of

palm Palm most commonly refers to: * Palm of the hand, the central region of the front of the hand * Palm plants, of family Arecaceae **List of Arecaceae genera * Several other plants known as "palm" Palm or Palms may also refer to: Music * Palm (ba ...

known from

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

flowers found in the early

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

Burdigalian The Burdigalian is, in the geologic timescale, an age or stage in the early Miocene. It spans the time between 20.43 ± 0.05 Ma and 15.97 ± 0.05 Ma (million years ago). Preceded by the Aquitanian, the Burdigalian was the first and longest w ...

stage

Dominican amber Dominican amber is amber from the Dominican Republic derived from resin of the extinct tree '' Hymenaea protera''. Dominican amber differentiates itself from Baltic amber by being nearly always transparent, and it has a higher number of fossil inc ...

deposits on the island of Hispaniola. The species is known from a single staminate flower and a single pistillate flower both preserved in the same piece of amber. The amber specimen bearing the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of sever ...

and

paratype In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype nor a syntype). O ...

is currently deposited in the collections of the

Oregon State University Oregon State University (OSU) is a public land-grant, research university in Corvallis, Oregon. OSU offers more than 200 undergraduate-degree programs along with a variety of graduate and doctoral degrees. It has the 10th largest engineering c ...

in Corvallis, Oregon, as number "Sd–9–101", where it was studied and described by George Poinar. Poinar published his 2002 type description for ''R. palaea'' in the ''

Botanical Journal of the Linnean Society The ''Botanical Journal of the Linnean Society'' is a scientific journal publishing original papers relating to the taxonomy of all plant groups and fungi, including anatomy, biosystematics, cytology, ecology, ethnobotany, electron microscopy, ...

'', Volume 139. The species' second name is taken from the Greek word ''palaios'' meaning "ancient". The amber specimen bearing the flowers was excavated from the La Toca mine northeast of

Santiago de los Caballeros Santiago de los Caballeros (; '' en, Saint James of the Knights''), often shortened to Santiago, is the second-largest city in the Dominican Republic and the fourth-largest city in the Caribbean by population. It is the capital of Santiago Prov ...

Dominican Republic The Dominican Republic ( ; es, República Dominicana, ) is a country located on the island of Hispaniola in the Greater Antilles archipelago of the Caribbean region. It occupies the eastern five-eighths of the island, which it shares with ...

Taxonomy

''R. palaea'' has been placed in the Arecoideae genus ''

Roystonea ''Roystonea'' is a genus of eleven species of monoecious palms, native to the Caribbean Islands, and the adjacent coasts of the United States (Florida), Central America and northern South America. Commonly known as the royal palms, the genus ...

'', which has ten modern genera native to the islands of the Caribbean, and to Florida, Central and South America.

Description

Many of the characters used to separate modern species of ''Roystonea'', including coloration, are not visible in the preserved flowers. The fossil flowers have darkened to shades of brown, with only the anthers retaining a light whitish color. Of the modern genera the ''R. palaea'' flowers are similar in structure, '' R. oleracea'' and '' R. dunlapiana'' both having a similar petal to sepal length ratio. ''R. palaea'' is most distinguishable from modern species by the large size of the calyx. The three species differ in the shape and length of their

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coine ...

s, ''R. palaea'' having the longest of the species while ''R. dunlapiana'' has the shortest. ''R. oleracea'' also possesses longer anthers at which are recurved at the tips, unlike ''R. palaea'', with anthers and straight. Along with the shorter sepal length ''R. dunlapiana'' also has purple anthers, differing from the light-colored anthers of ''R. palaea''.

Possible ecology

Of note is the damage which is present on the pistillate flower. One side of the flower is preserved, having the peranth ripped off exposing the center of the flower and the developing fruit, which has two scratches on the exposed side. Poinar proposes that the damages may have occurred due to an herbivore seizing the flower and subsequently dropping it in the soft tree resin, which afterward fossilized. This is supported by many of the modern ''Roystonea'' species having oily fruits that are eaten by a number of bird and bat species.

References

{{Taxonbar, from=Q7375270 †palaea Prehistoric angiosperms Miocene plants Miocene life of North America Burdigalian life Dominican amber Fossil record of plants Flora of Hispaniola Trees of the Dominican Republic Fossil taxa described in 2002 Taxa named by George Poinar Jr.