Palaeopsychops
| Palaeopsychops Temporal range: Ypresian
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| Palaeopsychops timmi holotype wing, SRIC SR 02-25-01 | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Neuroptera |
| Family: | Ithonidae |
| Genus: | †Palaeopsychops Andersen, 2001 |
| Species | |
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See text | |
Palaeopsychops is an extinct genus of lacewing in the moth lacewings family Ithonidae. The genus is known from Early Eocene fossils found in Europe, and North America and is composed of ten species. The ten species can be informally separated into two species groups based on veination of the forwings, the "European" and "North American" groups. When first described, the genus was placed in the family Psychopsidae, but later was moved to Polystoechotidae, which itself is now considered a subgroup of the moth lacewings.
Distribution & Age
The European species of Palaeopsychops are all known from the Early Eocene Fur Formation along the western Limfjord coast of Denmark.[1] Most of the 60 m (200 ft) thick formation is diatomites with an interspersed sequence of approximately 179 ash layers. Argon–argon radiometric dating of ash layer "+19", which is slightly lower in the strata then the "insect beds", has determined a 54.04 ± 0.14 million years ago age. [2]
Palaeopsychops species have been recovered from three locations in the Okanagan highlands, the Horsefly shales near Horsefly, British Columbia, the Coldwater Beds Quilchena site near Quilchena, British Columbia and the Klondike Mountain Formation in Republic, Washington, northern Ferry County, Washington. The Okanagan highlands are aged between 51.5 ± 0.4 million years ago for the Quilchena site to 49.4 ± 0.5 million years ago for the Klondike Mountain Formations Tom Thumb Tuff member.[2]
Paleoenvironment
The Fur formation represents a marine depositional environment of the inland water body which is ancestral to the North Sea. While the ancestral water body had an occasional opening to the Atlantic, it was entirely or almost entirely enclosed by land. The Fur formation outcrop is of a site that is an undetermined distance from the paleoshoreline with the preserved terrestrial flora and fauna suggested to have been carried from a shoreline to the north of the site by winds or drifting.[2] Analysis of the δ18O/δ16O isotope ratio found in mollusc shells in the formation indicates paleotemperatures were of a low megathermal mean annual temperature, though the presence in the paleobiota of thermophilic taxa could indicate a lower mean annual temperature combined with a higher coldest month mean temperature.[2]
All three Okanagan Highlands sites represent upland lake systems that were surrounded by a warm temperate ecosystem with nearby volcanism.[3] The highlands likely had a mesic upper microthermal to lower mesothermal climate, in which winter temperatures rarely dropped low enough for snow, and which were seasonably equitable.[4] The paleoforest surrounding the lakes have been described as precursors to the modern temperate broadleaf and mixed forests of Eastern North America and Eastern Asia. Based on the fossil biotas the lakes were higher and cooler then the coeval coastal forests preserved in the Puget Group and Chuckanut Formation of Western Washington, which are described as lowland tropical forest ecosystems. Estimates of the paleoelevation range between 0.7–1.2 km (0.43–0.75 mi) higher than the coastal forests. This is consistent with the paleoelevation estimates for the lake systems, which range between 1.1–2.9 km (1,100–2,900 m), which is similar to the modern elevation 0.8 km (0.50 mi), but higher.[4]
Estimates of the mean annual temperature have been derived from climate leaf analysis multivariate program (CLAMP) analysis of the Republic and Quilchena paleofloras, and leaf margin analysis (LMA) of all three paleofloras. The CLAMP results after multiple linear regressions for Republic gave a mean annual temperature of approximately 8.0 °C (46.4 °F), with the LMA gaving 9.2 ± 2.0 °C (48.6 ± 3.6 °F).[4] CLAMP results from Quilchena returned the higher 13.3 ± 2.1 °C (55.9 ± 3.8 °F) which was supported by the 14.8 ± 2.0 °C (58.6 ± 3.6 °F) returned from the LMA.[4][5] LMA of the Horsefly flora returned a mean annual temperature of 10.4 ± 2.2 °C (50.7 ± 4.0 °F). These are lower then the mean annual temperature estimates given for the coastal Puget Group, which is estimated to have been between 15–18.6 °C (59.0–65.5 °F). The bioclimactic analysis for Republic, Quilchena, and Horsefly suggest mean annual precipitation amounts of 115 ± 39 cm (45 ± 15 in) 130 ± 27 cm (51 ± 11 in) and 105 ± 47 cm (41 ± 19 in) respectively.[4]
History and classification
The genus was first described by Andersen (2001) from a series of 31 fore and hind wing part-counterpart fossils plus three partial body fossils found in the Fur Formation. Andersen chose the genus name as a combination of the psychopsid families nominal genus Psychops, itself a combination of the Greek words psyche and opsis meaning "butterfly" and "appearance", with the Latin word palaeo meaning "old". Andersen designated Palaeopsychops latifasciatus as the type species, and named three other species in the same paper, Palaeopsychops abruptus, Palaeopsychops angustifasciatus, and Palaeopsychops maculatus.[1]
Of the study material, the holotype specimens of all four species, along with paratypes for P. abruptus and P. angustifasciatus were deposited in the Geological Museum, University of Copenhagen. The four holoytypes plus P. abruptus paratype 1 were all declared by Andersen as danekræ, specimens of high scientific value to the Danish. Additional paratype fossils were spread out between a number of collections including the Fur Museum on Fur Island, the Moler Museum on Mors Island and private collections in Nykøbing Mors Denmark and in Germany.[1] The fifth species, Palaeopsychops dodgeorum, was described by Makarkin and Archibald (2003) two years later . The holotype hindwing was found at the Coldwater Beds Quilchena site in British Columbia. The only known specimen of the species, was included in the university of Alberta collections at the time of study.[6] Archibald and Makarkin (2006) added five additional species in the genus, bringing to known species count to ten with one additional Danish species Palaeopsychops quadratus, and four Okanagan Highlands species. Palaeopsychops dodgeorum added a second species from Quilchena, while one species Palaeopsychops setosus was described from the more northern Horsefly shales site and two species Palaeopsychops marringerae and Palaeopsychops timmi were detailed from the southern most Klondike Mountain Formation in Washington.[2]
Andersen (2001) placed the new genus into the family Psychopsidae based on the large size of the wings, the dense vein structure, and his interpretation that the subcosta (Sc), anterior radial trace (R1), and anterior sectoral trace (R2) veins merged near the wing apex forming a vena triplica structure. As such, Andersen placed the genus within the psychopsids, while noting at the time the species were larger than any other member species and notably similar to the Florissant Formation species Polystoechotites piperatus, which was placed in the psychopsid family at the time as "Propsychopsis" piperatus. Makarkin and Archibald (2003) called the psychopsid into question based on examination of the P. latifasciatus images in the type description and the venation of P. douglasae. While the R1 and Sc veins do merge into a single vein, they determined the R2 did not merge with them. Instead the R2 runs parallel to the other two and then to the fused vein and terminates at the wing margin seperately. As such, it lacked the key venation character that unites the psychopsids. After examining all described neuropteran families they tentatively placed the genus within the "giant lacewing" family Polystoechotidae.[6] With the addition of the 2006 species and description of the form genus Polystoechotites Archibald and Makarkin reaffirmed the placement of Palaeopsychops within the family Polystoechotidae and noted the fore-wing species fall into two informal groups the "European" and "North American" groups. They were hesitant to place strong weight on the groupings as the scattered crossveins uniting the 3 North American species is a character seen in other Ithonid genera from North America.[2] Winterton and Makarkin (2010) documented phylogenetic and morphological analysis of the families Ithonidae and Polystoechotidae in which the two families were found to form a monophyletic clade.[7] Due to several of the traditional ithonidae genera forming a sister group within the polystoechotid genera and a lack of characters specific to only one family or the other, Winterton and MAkarkin merged the two into a single expanded Ithonidae family.[7] Subsequent to the expansion of Ithionidae an overview of the family was given by Zheng et al (2016) in which they informally grouped the genera into three genus groups, the Ithonid genus group, the Polystoechotid genus-group, and the Rapismatid genus group, with Palaeopsychops placed in the Polystoechotid genus-group.[8]
Description
P. abruptus
Fur Formation
P. angustifasciatus
Fur Formation
P. dodgeorum
Coldwater Beds, Quilchena Trichosors
P. douglasae
P. douglasae was described from the holotype hindwing collected by paleoichthyologist Mark Wilson from the Quilchena locality. Archibald & Makarkin (2006) picked the specific epithet as a matronym honoring Sheila Douglas for her paleoentomology work on British Columbian fossils. The part side of the holotype is broken into two sections with areas of the midwing and wing base missing, and little color patterning visible. The couterpart is better preserved, showing distinct color patterning and more of the cross-venation in the dark-colored area of the color-pattern. The dark coloration is centered as a u-shaped patch in the central portion of the wing, lightening in tone near the rear wing margin, lacking any coloration at the wing base and apex excepting a very thin strip of darkening along the apical margin. The wing is 42 mm (1.7 in) by 19 mm (0.75 in) at the widest point, with a distinctly undulant rear margin, a trait that appears rarely in neuropteran species. The undulations of the rear margin give a slightly falcate outline to the wing apex.[2]
P. latifasciatus
P. latifasciatus is one of the Fur Formation species group, being described by Andersen (2001) from a holotype and several paratype forewings. The name was derived from a combination of the Latin words latus meaning "broad" and fasciatus meaning "banded". The forewings range between 3.7–4.4 cm (1.5–1.7 in) in length, and are just over twice as long as they are at the widest point. The preserved color pattering shows a trio of broad straight dark toned stripes crossing the wing at an oblique angle. A fourth dark stripe is present near the wing apex, though it is not distinctly separated from the dark patterning of the posteroapical border. Additional dashes and spots of dark tone are spread across the wing, with the heaviest concentration in the costal space between the larger color bands.[1] While the wings are similar to those of P. abruptus the crossveins in the costal space and the broad dark tone stripes passing through the subcostal and R1 spaces.[2]
P. maculatus
P. maculatus is the only Danish species described from a hindwing,[2] though it was first interpreted as a fore wing by Andersen (2001). The holotype was collected by Henrik Madsen from the Ejerslev Molergrav locality of the Fur Formation on Mors,[1] and is complete though indistinctly preserved. Andersen (2001) selected the Latin maculata, meaning "spotted" for the origin of the specific name noting the distinctly different color patterning if it compared to the other three Danish species at the time.[1] The darkened area is concentrated in the center region of the wing with the lower margin following the outer gradate series and narrow dark stripes extending from the central region upwards towards the upper margin crossing the subcostal space. The remainder of the wing lightens to clear along the base, margins, and apex. The wing is 17.5 mm (0.69 in) wide by 40 mm (1.6 in) long with no visible trichosors or nygmata. While the wing is similar in color pattern and proportions to P. setosus, the inner gradate crossveins are placed closer to the outer gradate series, and the basal area of the wing is notably wider then that of P. setosus. Archibald and Makarkin (2006) noted that P. maculatus and P. latifasciatus might one species, based on the similar coloration of the darkened stripes when they cross the subcostal space. However since P. latifasciatus is kown only from fore wings while P. maculatus is known only from a hind wing, the species status remains speculative until articulated fore and hind wings are found.[2]
P. marringerae
Klondike Mountain Formation
P. quadratus
Fur Formation
P. setosus
P. setosus is described from a single hindwing found in the Horsefly Shales and described by Archibald and Makarkin (2006), who named the species from the Latin setosus meaning bristly or hairy. the wing is 17 mm (0.67 in) wide by 40 mm (1.6 in) long with a length/width ratio of 2.35. Overall the wing membrane is dark in color tone lightening along the margins and at the apex and preserved section of the base. The color patterning and proportions of the wing are notably similar to the Danish P. maculatus, though P. setosus has a larger distance between the inner gadate crossavein series, and the outer gradate series, and also by the narrower basal section of the wing. The wing does not have preserved nygmata or marginal trichosors, but a dense region of the wings basal area is covered in a setose band. The band is dominated by 0.15–0.30 mm (0.0059–0.0118 in) long macrotrichia which uniformally cover the region with no differentiation when crossing veins. The upper margin of the bands is indistinct grading from sparse to denser setal covering, while the lower band margin ends abruptly with the the longest setae present of the band.[2] The P. setosus setae band is distinct among the ithonids, and long setation is only seen in the living families Ascalaphidae and Sialidae. Within the Neuropteran fossil record, long dense setae is seen in the families Parakseneuridae and Kalligrammatidae.[9]
P. timmi
Klondike Mountain Formation
References
- ^ a b c d e f Andersen, S. (2001). "Silky lacewings (Neuroptera: Psychopsidae) from the Eocene-Paleocene transition of Denmark with a review of the fossil record and comments on phylogeny and zoogeography" (PDF). Insect Systematics & Evolution. 32 (4): 419–438.
- ^ a b c d e f g h i j k Archibald, S. B.; Makarkin, V. N. (2006). "Tertiary giant lacewings (Neuroptera: Polystoechotidae): revision and description of new taxa from western North America and Denmark" (PDF). Journal of Systematic Palaeontology. 4 (2): 119–155.
- ^ Archibald, S.; Greenwood, D.; Smith, R.; Mathewes, R.; Basinger, J. (2011). "Great Canadian Lagerstätten 1. Early Eocene Lagerstätten of the Okanagan Highlands (British Columbia and Washington State)". Geoscience Canada. 38 (4): 155–164.
- ^ a b c d e Greenwood, D.R.; Archibald, S.B.; Mathewes, R.W; Moss, P.T. (2005). "Fossil biotas from the Okanagan Highlands, southern British Columbia and northeastern Washington State: climates and ecosystems across an Eocene landscape". Canadian Journal of Earth Sciences. 42 (2): 167–185. Bibcode:2005CaJES..42..167G. doi:10.1139/e04-100.
- ^ Mathewes, R. W.; Greenwood, D. R.; Archibald, S. B. (2016). "Paleoenvironment of the Quilchena flora, British Columbia, during the early Eocene climatic optimum". Canadian Journal of Earth Sciences. 53 (6): 574–590.
- ^ a b Makarkin, V. N.; Archibald, S. B. (2003). "Family affinity of the genus Palaeopsychops Andersen with description of a new species from the Early Eocene of British Columbia, Canada (Neuroptera: Polystoechotidae)". Annals of the Entomological Society of America. 96 (3): 171–180.
- ^ a b Winterton, SL; Makarkin, VN (2010). "Phylogeny of Moth Lacewings and Giant Lacewings (Neuroptera: Ithonidae, Polystoechotidae) Using DNA Sequence Data, Morphology, and Fossils". Annals of the Entomological Society of America. 103 (4): 511–522. doi:10.1603/an10026.
- ^ Zheng, B.; Ren, D.; Wang, Y. (2016). "Earliest true moth lacewing from the Middle Jurassic of Inner Mongolia, China" (PDF). Acta Palaeontologica Polonica. 61 (4): 847–851.
- ^ Yang, Q.; Makarkin, V. N.; Winterton, S. L.; Khramov, A. V.; Ren, D. (2012). "A remarkable new family of Jurassic insects (Neuroptera) with primitive wing venation and its phylogenetic position in Neuropterida". PLoS One. 7 (9). doi:10.1371/journal.pone.0044762.
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