The Limoniidae are a large group
of small-to-medium sized Crane Flies, Tipuloidea, with coloured or patterned
wings, which are sometimes shortened or otherwise reduced. There are over 11
000 extant species within the family Limoniidae, divided into four subfamilies,
the Chioneinae, Dactylolabinae, Limnophilinae and Limoniinae, with phylogenetic
analyses suggesting that the Dactylolabinae are likely to be the oldest group.
All members of the subfamily Dactylolabinae are currently placed within a
single genus, Dactylolabis, with
living members divided into four subgenera, Bothrophorus,
Coenolabis, Dactylolabis and Eudactylolabis.
Of these subgenera only Dactylolabis has
a fossil record, being known from Eocene Baltic Amber, with four extinct
subgenera, Aurolabis, Eobothrophorus, Eolabis and Idiolabis
also used to describe Baltic Amber species.
In a paper published in the
journal Palaeontologica Electronica in January 2015, Iwona Kania of the Department
of Environmental Biology at Rzeszów University and Wiesław Krzemiński of the
Institute of Systematic and Evolution of Animals at the Polish Academy of Sciences describe a new species of Dactylolabis
from Eocene Baltic Amber.
The new species is placed in the
subgenus Idiolabis and given the
specific name ryszardi, in honour of Ryszard Szadziewski, an expert on fossil and living flies. Dactylolabis (Idiolabis) ryszardi i described from a single male
specimen 7.3 mm in length, with 9.76 mm wings.
Dactylolabis (Idiolabis) ryszardi, male specimen in lateral view. Kania & Krzemiński
(2015).
The long-lived status of the
subgenus Dactylolabis (Dactylolabis), with all other described
subgenera being either modern or Eocene, has recently been questioned. A
phylogenetic analysis carried out by Kania and Krzemiński suggests that all the
described subgenera are indeed discreet evolutionary lineages (although some of
the Eocene subgenera contain only a single species), though the Eocene and
modern members of Dactylolabis (Dactylolabis) are not particularly
closely related.
Kania and Krzemiński observe that
while the Eocene forests of Fennoscandia, which produced the Baltic Amber, were
a warm-forest environment with little seasonal variation, similar to forests
found closer to the equator today, these forests covered a vast geographical
range, extending a long way north-to-south and also containing a wide range of
altitudinal variation. This suggests that these forests would have had a high
number of different environments within them, as is the case with modern
tropical forests, but that this ecological variation is hidden somewhat by the
nature of the Baltic Amber deposits, which contain river-transported material
carried from many different areas by the action of vast ancient waterways.
Modern members of the subgenus Dactylolabis (Dactylolabis) are widely distributed, and have are tolerant of a
broad range of environments, while the other modern subgenera of Dactylolabis are much more limited, with
more specialized environmental requirements. Kania and Krzemiński suggest that
the same may have been the case in the Eocene, with subsequent environmental
change wiping out the more specialized groups while the more tolerant Dactylolabis (Dactylolabis) survived. This scenario makes it highly likely that Dactylolabis (Dactylolabis) is in fact polyphyletic as well as morphologically
conservative, with more specialized forms repeatedly arising from within this
subgenus
See also…
Winter Crane Flies from the Middle Jurassic Jiulongshan Formation of Inner Mongolia.Winter Crane Flies (Trichoceridae) are large True Flies (Diptera) with a (slightly erroneous) reputation for being tolerant of cold conditions. In fact a few species are capable of remaining active in winter, with some even mating and laying eggs beneath snow cover, but...
A Non-biting Midge from Late Eocene Ukrainian amber.Non-biting Midges (Chironomidae) are small Flies closely related to the Biting Midges, Solitary Midges and Blackflies. They closely resemble Mosquitoes, but despite their appearance and relationships, they...
A new species of Axymyid Fly from the northwest United States.Axymyids are medium sized, stout bodied, True Flies (Diptera) related to the Gnats, Midges, Mosquitoes and Crane Flies. They have a fossil record going beck to the Jurassic, but are rare today, with only six described species.
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