Friday, 30 January 2015

Comet C/2014 Q2 (Lovejoy) reaches perihelion.

Comet C/2014 Q1 (Lovejoy) reached its perihelion (the closest point on its orbit to the Sun) on Friday 30 January 2015, when it will be 1.29 AU from the Sun (i.e. 1.29 times the average distance at which the Earth orbits the Sun). It is potentially visible to naked eye observers in the constellation of Aries, though it would be better to try to observe it with a pair of binoculars or small telescope. It will remain potentially visible to naked eye observers for the next week, moving into the constellation of Andromeda on 1 February. After this it will only be possible to view the comet with binoculars or a telescope from the Northern Hemisphere and not at all from the Southern Hemisphere. It will move into the constellation of Perseus on 15 February, then Cassiopeia on 1 March, Cephus on 8 May, Ursa Minor on 1 June, Draco on 22 July, Boötes on 15 August, Heracles on 8 September and Corona Borealis on 15 September, though by the northern summer it will be impossible to see it without a fairly large telescope.

C/2014 Q2 (Lovejoy) as seen on 20 December 2014 from Australia. Roger Groom/Astrophotography.

Comet C/2014 (Lovejoy) was discovered on 17 August 2014 by Australian astronomer Terry Lovejoy. The name C/2014 Q2 (Lovejoy) implies that it is a non-periodic comet (C/) (all comets are, strictly speaking, periodic since they all orbit the Sun, but those with periods longer than 200 years are considered to be non-periodic), that it was the second comet (comet 2) discovered in the second half of August 2014 (period 2014 Q), and that it was discovered by Lovejoy.

The calculated orbit of C/2014 Q2 (Lovejoy). JPL Small Body Database Browser.

C/2014 Q2 (Lovejoy) is calculated to have a 13 914 year orbital period and a highly eccentric orbit tilted at an angle of 80.3° to the plain of the Solar System that takes it from 1.29 AU from the Sun at perihelion (129% of the distance between the Earth and the Sun) to 1156 AU from the Sun at aphelion, which is 1156 times as far from the Sun as the Earth, over 38 times as far from the Sun as Neptune, 23 times as far from the Sun as the outer limit of the Kuiper Belt, but still within the inner Oort Cloud.

See also…

Comet C/2014 E2 (Jacques) passed the Earth at a distance of 0.56 AU (i.e. 56% of the distance between the Earth and the Sun, about 84 million km) on Thursday 28 August 2014. This is not a close approach (it is further than the distance between Mercury and the...

Comet C/2012 K1 (PANSTARRS) will reach its perihelion (the closest point on its orbit to the Sun)  on Wednesday 27 August 2014, though it will not be visible...

The Rosetta Spacecraft moved into position alongside Comet 67P/Churyumov–Gerasimenko on Wednesday 6 August 2014, the first spacecraft to reach a cometary target, and ten years after the mission was launched. It...

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A new specimen of Microraptor from western Liaoning Province, China.

In December 2000 Xing Xu, Zonghe Zhou and Xioalin Wang of the Institute of Vertebrate Paleontologyand Paleoanthropology of the Chinese Academy of Sciences described a new species of Dromaeosaurid from the Early Cretaceous Jiufotang Formation of western Liaoning Province in a paper in the journal Nature. This was the smallest non-Avian Dinosaur ever found, and showed a remarkable similarity to the earliest Birds, including an extensive covering of feathers.

This Dinosaur was named Microraptor zhaoianus, and since this time a number of further specimens of Microraptor have been discovered and two further species have been described (though these are not universally accepted). Remarkably the new specimens have revealed further Bird-like features, including the presence of two pairs of wings (unlike in Birds, the hindlimbs of Microraptor were also modified for flight).

In a paper published in the American Museum Novitates on 22 December 2014, Rui Pei of the Division of Paleontology at the American Museum of NaturalHistory, Quangou Li of the State Key Laboratory of Biogeology and Environmental Geology at the China University of Geosciences, Qingjing Meng of the BeijingMuseum of Natural History, Ke-Qin Gao of the School of Earth and Space Sciences at Peking University and Mark Norell, also of the Division of Paleontology at the American Museum of Natural History, describe a new specimen of Microraptor zhaoianus from the same deposits as the original (and all subsequent) specimens.

The new specimen of Microraptor zhaoianus, view of entire mounted slab. Pei et al. (2014).

The new specimen is exceptionally well preserved, possessing a number of features not seen in other specimens. It shows several traits previously described that clearly mark Microraptor out as a Dromaeosaur, including extremely elongate prezygapophyses and chevrons (re-enforcing structures that help support the rigid tail in Dinosaurs – check), a vertical process on the posteromedial corner of the retroarticular process of the mandible and a reduced manual phalanx III-2, and in addition another Dromaeosaur trait not seen in any previously described specimen, dorsal displacement of the maxillary fenestra and a large quadrate foramen.

Skull and mandible of the new specimen of Microraptor zhaoianus, photograph (top) and interpretive drawing (bottom). Abbreviations: aof, antorbitalfenestra; emf, external mandibularfenestra; hy, hyoid; j, jugal; l, lacrimal; lan, left angular; lar, left articular; ld, left dentary; lfr, left frontal; lsp, left splenial; m, maxilla; mf, maxillary fenestra; n, nasal; na, naris; pa, parietal; pm, premaxilla; po, postorbital; pra, prearticular; q, quadrate; qj, quadratojugal; ran, right angular; rar, right articular; rfr, right frontal; sa, surangular; sq, squamosal. Pei et al. (2014).

The new specimen also shows a number of features in common with early Troodontids which have been reported in other specimens, such as a short subnarial process on the premaxilla, smaller teeth on the premaxilla than on the maxilla, no denticles on the anterior carinae of the maxillary teeth and a Troodontid-like articulation of the foot. In addition this specimen has a better-preserved maxilla and face than previous specimens, showing other Troodontid-like features, such as a shallow main body of the bone and a slender interfenestral bar combined with an enlarged maxillary fenestra. This supports the close relationship of the Dromaeosaurs and Troodontids previously proposed; the two are currently grouped together to form the Deinonychosauria, to the exclusion of other Maniraptors, including the Birds.

However the arrangement of the rib-cage in the new specimen is probably its most remarkable feature, this preserves gastralia and uncinate processes, features known from a variety of Theropod Dinosaurs including other Dromeaosaurs, but in this case remarkably similar to those of the early Bird Confuciusornis. This suggests that respiration in Microraptorwas similar to that in early Birds, lending further weight to the idea that it could also fly.

The rib cage of the new specimen of Microraptor zhaoianus. Abbreviations: dr, dorsal rib; h, humerus; lms, left medial segment of gastralia; rls, right lateral segment of gastralia; rms, right medial segment of gastralia; sc, scapular; st, sternum; up, uncinate process. Pei et al. (2014).

See also… species of Dromaeosaur from the Early Cretaceous of Utah.                                        Dromaeosaurs were small Therapod Dinosaurs, thought to have been the group most closely related to... footprints from the Early Cretaceous of Ganzu Province, China.            The Deinonychosaurs are the group of dinosaurs most closely related to the birds. They are divided into two groups, the Dromaeosaurs (popularly known as 'Raptors') and the Troodontids, which share a common hindlimb morphology, with two digits used to support... did raptors use their claws? (and did it help them learn to fly?)                                                      The Dromaeosaurs were a group of small, feathered dinosaurs closely related to the birds. They are commonly referred to as 'raptors' on account of an enlarged claw on each foot which was held clear of the ground when walking and is generally assumed to have been a weapon; this claw resembles that of a bird of prey, which are also referred to as 'raptors'. This claw was also present in the other group...
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Thursday, 29 January 2015

The enigmatic Pleistocene Amphibians of Okinawa Island.

In the late 1960s and early 1970s a series of anthropological excavations were carried out at Minatogawa Fissure on southern Okinawa Island, producing a number of Late Pleistocene Human bones, as well as associated bones of other terrestrial vertebrates. Whilst most of the bones were from animals still found on Okinawa, or neighbouring members of the central Ryukyu Islands, or at least extinct animals thought to have been endemic (native) to the islands, a number of Frog species were reported which are today absent from the Ryukyus, but found in other parts of Japan. This is puzzling, as the Ryukyu Islands are generally thought to be biogeographically distinct from the rest of Japan; eleven out of fourteen Amphibian species found in the Central Ryukyus today are found nowhere else, two species are also found in southern China, with only a single species, the wide ranging Marsh Frog, Fejervarya kawamurai, is shared with the rest of Japan, and this species is also found in southern China and is thought likely to have reached the Central Ryukus in a separate dispersal event from the mainland. A specimen of Polypedates leucomystax, a Southeast Asian Frog otherwise thought to have been introduced to the islands in the mid twentieth century was also reported.

In addition these excavations yielded a number of Frog species still found in the on the island, but restricted to the moister, more forested northern part of the island. This is problematic, as the Pleistocene climate of Okinawa is interpreted to have been cooler and drier, which would cause such frogs to have had a more limited range, rather than an expanded one, and also because pollen associated with the tree species now found in the woodland on the north of the island has not been found here, implying that the south of the island was as lacking in woodland in the Pleistocene as it is today. Furthermore, the fissure is in an area of limestone karst (soft, absorbent and highly porous limestone), which would make it hard for bodies of standing water to form here under any circumstances.

In a paper published in the journal Palaeontologica Electronica in January 2015, Yasuyuki Nakamura of the Tropical Biosphere Research Center at the University of the Ryukyus and Hidetoshi Ota of the Institute of Natural and Environmental Sciences at the University of Hyogo and the Museum of Nature and Human Activities in Hyogo, Frog and Newt bones recovered from a more recent study at Minatogawa Fissure, as well as new excavations at the nearby Sashiki Fissure.

Maps of the Ryukyu Archipelago (1, 2) and Okinawajima Island (3). The map of Okinawajima shows topography, distribution of the Pleistocene limestone, and study sites.Nakamura & Ota (2015).

The sediments in the Minatogawa Fissure have been dated to about 15 670 years ago, towards the end of the Last Glacial Maximum. It is located in the Minatogawa Formation above the Yuhi River on the southeastern part of the island. Nakamura and Ota were unable to access the material from the original 1960s and 1970s excavations, nor any details of how the material was analysed (the previous publications covering the material simply listed the species). They were, however, able to access a series of Amphibian bones obtained by water-screening sediments from the site during a more recent excavation at the fissure in 1998-2001. These were compared to specimens of Amphibians from the Ryukus, other areas of Japan, and adjacent areas such as the Korean Peninsula.

The 1998-2001 Minatogawa Fissure material yielded a single humerus assigned to a female Namiye’s Frog, Limnonectesnamiyei, a species today found on northern, but not southern Okinawa and two humeri and two ilia attributed to female Holst’s Frogs, Babinaholsti, another species found today on the northern part of the island (leg bones are the most robust in Frogs, and therefore the most commonly preserved; it is usually possible to tell the sex of a From from its humeri).

Left female humerusfrom Minatogawa Fissure, referred to Limnonectes namiyei, lacking the proximal and distal parts and the crista ventralis in ventral (1), medial (2) and dorsal (3) views. Abbreviations: cr.par, crista paraventralis; fo.div, fossula dividens;, olecranon scar; stm, spina tuberculi medialis. Scale bar is 5 mm. Nakamura & Ota (2015).

Much more abundant were bones of the Okinawa Tip-nosed Frog, Odorrana narina, with 21 right and 24 left female humeri, 16 right and 16 left male humeri and 22 right and 31 left ilia found in the material. This species is also found on the northern part of Okinawa today.Another abundant species was the Ryukyu Brown Frog, Rana ulma, with 41 right and 48 left female humeri, one left male humerus and eight right and nine left ilia found in the sample. This species is also found on northern Okinawa today.

Also present was a right humerus attributed to a female Ryukyu Kajika Frog, Buergeria japonica, a species still found on the southern part of Okinawa, and a pair of humeri of undetermined sex assigned to the Okinawa Green Tree Frog, Rhacophorus viridis viridis, also found on the southern part of Okinawa today.

Right femalehumerus from Minatogawa Fissure, referred to Buergeria japonica, lacking the proximal part in ventral (1), medial (2), and dorsal (3) views. Abbreviations:, crista lateralis;, crista medialis; e.cap, eminentia capitata; ep.ul, epicondylus ulnaris;, olecranon scar. Scale bar is 1 mm. Nakamura & Ota (2015).

Two species of Newt were also recovered from the material. Eight atlantes (the first vertebra after the skull), at least postatlantal precaudal vertebrae, 20 right and 15 left humeri and 11 right and 12 left femora were assigned to the Sword-tailed Newt, and three postatlantal precaudal vertebrae and one right femur were attributed to Anderson’s Crocodile Newt, Echinotriton andersoni, both of with are still present on southern Okinawa.

The Sashiki Fissure lies 6 km to the northeast of the Minatogowa Fissure in an uplifted terrace of the Naha Formation on the Chinen Peninsula. The fissure is a sinkhole that was exposed by limestone miners, then excavated by archaeologists from 2004 till 2008. The fissure yielded two separate deposits, a lower bed dated to between 28 729 and 31 745 years ago, around the beginning of the last glacial maximum, and an upper bed dated to between 3904 and 5558 years ago, during the Middle Holocene; these beds resting in separate depressions and not overlying one-another, though there is a thin layer at the top of the older deposits dated to about 7445 years ago (which did not yield any vertebrate fossils).

Photograph of the Sashiki Fissure (left) and schematic figure showing the structure of the fissure (right). In the right figure, broken lines represent the outline of the fissure behind rock, shaded areas represent studied sediments, and open circles represent the locations of the dating samples. Nakamura & Ota (2015).

The lower deposits at Sashiki yielded a single left ilium referred to Namiye’s Frog, Limnonectes namiyei, one right and five left female humeri, oneright and one left male humeri and six right and three leftilia assigned to Holst’s Frog, Babina holsti, and five right and five left female humeri, two right and one left male humeri and four right and one left ilia assigned to Ishikawa’s Frog, Odorrana ishikawae, all species found on the north of the island today.

Right female humerus in ventral (5), medial (6) and dorsal (7) views; (8–10) right male humerus lacking the proximal part in ventral (8), medial (9), and dorsal (10) views; and (11), right ilium lacking the anterior part in lateral view. Abbreviations: acet, acetabulum; acet.m, acetabular margin; cr.dors, crista dorsalis;, crista lateralis;, crista medialis; cr.par, crista paraventralis; cr.ven, crista ventralis; e.cap, eminentia capitata; ep.rad, epicondylus radialis; ep.ul, epicondylus ulnaris; fo.div, fossula dividens;,ilial shaft; p.asc, pars ascendens; stm, spina tuberculi medialis;, supracetabular fossa; tub.sup, tuber superior. Scale bars equal 5 mm. Nakamura & Ota (2015).

The Okinawa Tip-nosed Frog, Odorrananarina, which was one of the most abundant Frogs in the Minatogowa Fissure, but which is only found on the north of the island today, is represented in the lower Sashiki deposits by only four right and four left female humeri, oneright male humerus, one pelvic girdle and one left ilium.

Pelvic girdle: fused right and left ilia (lacking anterior parts) with the ischium and the pubis, in right lateral view. Abbreviations: acet, acetabulum; acet.m, acetabular margin; cr.dors, crista dorsalis;, ilial shaft; p.asc, pars ascendens;, supracetabular fossa; tub.sup, tuber superior. Scale bars equal 5 mm. Nakamura & Ota (2015).

The other abundant Frog in the Minatogowa Fissure, the Ryukyu Brown Frog, Rana ulma, which is also absent from the south of the island today, is even more abundant in the lower Sashiki deposits, with 108 right and 68 left female humeri, 44 right and 43 left male humeri and 46 right and 47 left ilia assigned to this species.

Fossils referred to Rana ulma. (1–3), right female humerus in ventral (1) medial (2) and dorsal (3) views; (4–6)right male humerus in ventral (4) medial (5) and dorsal (6) views; (7) right iliumin lateral view. Abbreviations: acet, acetabulum; acet.m, acetabular margin; cr.dors, crista dorsalis;, crista lateralis;, crista medialis; cr.par, crista paraventralis; cr.ven, cristaventralis; e.cap, eminentia capitata; ep.ul, epicondylus ulnaris; fo.div, fossula dividens;, ilial shaft;, olecranon scar; p.asc, pars ascendens; stm, spina tuberculi medialis;, supracetabular fossa; tub.sup, tuber superior. Arrows indicate the proximal ends of the crista paraventralis. Scale bars equal 1mm. Nakamura & Ota (2015).

The Okinawa Green Tree Frog, Rhacophorus viridis viridis, which was present in the Minatogowa Fissure and which is still found on south Okinawa today, is represented in the lower Sashiki Fissure by two right and five left female humeri, one left humeri of indeterminate sex, one right ilium and one pelvic girdle.

Pelvic girdle of Rhacophorus viridis viridis (fused right and left ilia lacking anterior parts withthe ischium) in left lateral view. Abbreviations: acet, acetabulum; acet.m, acetabular margin; cr.dors, crista dorsalis;, ilial shaft; p.asc, pars ascendens; pre.acet, preace tabular zone;, supracetabular fossa; tub.sup, tuber superior. Scale bars equal 1mm. Nakamura & Ota (2015).

The Sword-tailed Newt, Cynops ensicauda, is represented in the lower Sashiki Fissure by two right and one leftmaxillae, one parietal-prootic-exoccipital, one left frontal, two right squamosals, six right and three left dentaries, five atlantes, 108 postatlantal precaudal vertebrae, 14 right and 11 left ribs, 41 right and 44 left humeri and 51 right and 41 left femora.

Fossils referred to Cynops ensicauda. (1–4) Postatlantal precaudal vertebra in anterior (1) left lateral (2) dorsal (3) and ventral (4) views; (5 and 6) atlas in anterior (5) and left lateral (6) views; (7) parietal-prootic-exoccipital in dorsal view; (8) right maxilla in lateral view; (9) right dentary in medial view; (10) right rib in posterior view; (11) right humerus in lateral view; and (12) right femur in posterior view. Abbreviations: con, condyle; diap, diapophyses;, epipleural processes; neu.sp, neural spine; n.prep, notch for prearticular; parap, parapophyses;, posterior process; subd.d, subdental ditch; zygap, zygapophyses. The arrow in 12 indicates a concavity. Scale bars equal 1 mm. Nakamura & Ota (2015).

Anderson’s Crocodile Newt, Echinotriton andersoni, is represented in the lower Sashiki Fissure unit by 11 right and 19 leftmaxillae, seven right and six left frontals, one parietal-prootic-exoccipital, nine right and nine left squamosals, three right and two left quadrates, 28 right and 42 left dentaries, 11 atlantes, 290 postatlantal precaudal vertebrae, 89 right and 92 left ribs, 68 right and 76 left humeri and (71 right and 92 left femora.

In the upper Sashiki Fissure unit, which is Middle Holocene in age, none of the species currently confined to northern Okinawa is present.

One species found in southern Okinawa today, and absent from the Pleistocene deposits is the Okinawa Narrow-mouthed Toad, Microhylao kinavensis, which is represented in the upper Sashiki Fissure deposits by two right ilia.

Right ilium of Microhylao kinavensisin lateral view, tub.sup, tuber superior. Scale bar equals 1mm. Nakamura & Ota (2015).

Also present in the upper unit at the Sashiki Fissure are one left ilium of the Ryukyu Kajika Frog, Buergeria japonica, one male left humerus of the Okinawa Green Tree Frog, Rhacophorus viridis viridis, and one right maxilla of the Sword-tailed Newt, Cynops ensicauda.

This study presents a very different view of the Pleistocene Amphibian fauna of southern Okinawa, with no species not found on the island today found in either the Late Pleistocene or Middle Holocene deposits, and the introduced Polypedates leucomystax absent from even the Holocene deposits. This leads Nakamura and Ota to conclude that the previous identifications of a range of exotic Frogs in Late Pleistocene deposits from the Minatogawa Fissure as erroneous.

The situation with Frogs found today on the north of the island is more complex, with Nakamura and Ota able to confirm the presence and even abundance of several north Okinawan species in Late Pleistocene deposits from the south of the island. This is highly problematic, as all previous evidence has suggested that the Late Pleistocene climate of the island was drier than today, with the south of the island less able to support such moisture loving species. Neither should pools of standing water, necessary for the survival of many of these species, form on the karst terrain that produced the fossils in anything short of a major flood event.

Maps showing current distributions (shaded areas) of five forest Frogs (Limnonectes namiyeia, Babina holstia, Odorrana ishikawaea, Odorrana narinaa, and Rana ulmaa, and the Newt Echinotriton andersonia on Okinawajima Island and adjacent islets. ‘?’ Denotes a population lacking a record or observation in the past 30 years. Nakamura & Ota (2015).

Nakamura and Ota observe that while the limestone areas of southern Okinawa are more-or-less free from streams or bodies of standing water, due to the drainage provided by the highly porous limestone, they are home to several natural springs, fed by waters flowing along the top of the water impermeable Shimajiri Group, which underlies the limestone units in places where these units are relatively thin or the limestone becomes slightly more dense (where water flowing through a rock body encounters a less porous area it must go somewhere, and tends to rise to the surface). They therefore suggest that in the Late Pleistocene the Minatogawa and Sashiki Fissures might have been home to such springs, providing standing bodies of water, which could have supported the moisture-loving Amphibians found preserved in the deposits there.

None of these species are present in the Middle Holocene deposits, suggesting that any such springs did not last beyond the last Pleistocene glaciation, and that the Amphibians of Okinawa Island had reached roughly their modern distributions by this time.

See also… new species of Salamander from the Early Cretaceous of Western Siberia.                Salamanders, Caudata, are one of the three extant groups of Lisamphibians, along with Frogs, Anura, and Caecilians, Gymnophiona. The earliest fossil Salamanders known date from the Middle Jurassic...
The Cambay Shale formation from the Vastan Lignite Mine to the northeast of Surat in Gujarat State, India, has produced a diverse and significant Vertebrate...
The earliest known Frogs in the fossil record hail from the earliest Triassic of Madagascar, though it is thought the group probably has its origins deeper in the Permian. A number of Frogs have been described from the Early Cretaceous Jehol Biota, a fossil Lagarstätte (rich fossil deposit) from...
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Magnitude 3.8 Earthquake in Rutland, England.

The British Geological Survey recorded a Magnitude 3.8 Earthquake at a depth of 8 km between the villages of Ashwell and Market Overton in Rutland, England, at about 10.25 pm GMT on Wednesday 28 January 2015. There are no reports of any damage or injuries associated with this event, though it was exceptionally large for an English Earthquake, and people have reported feeling it from as far away as Dudley in the West Midlands and Huddersfield in West Yorkshire.

 The approximate location of the 28 January 2015 Rutland Earthquake and locations where people have reported feeling the event. British Geological Survey.

Earthquakes become more common as you travel north and west in Great Britain, with the west coast of Scotland being the most quake-prone part of the island and the northwest of Wales being more prone  to quakes than the rest of Wales or most of England. However, while quakes in southern England are less frequent, they are often larger than events in the north, as tectonic presures tend to build up for longer periods of time between events, so that when they occur more pressure is released.

The precise cause of Earthquakes in the UK can be hard to determine; the country is not close to any obvious single cause of such activity such as a plate margin, but is subject to tectonic pressures from several different sources, with most quakes probably being the result of the interplay between these forces.

Britain is being pushed to the east by the expansion of the Atlantic Ocean and to the north by the impact of Africa into Europe from the south. It is also affected by lesser areas of tectonic spreading beneath the North Sea, Rhine Valley and Bay of Biscay. Finally the country is subject to glacial rebound; until about 10 000 years ago much of the north of the country was covered by a thick layer of glacial ice (this is believed to have been thickest on the west coast of Scotland), pushing the rocks of the British lithosphere down into the underlying mantle. This ice is now gone, and the rocks are springing (slowly) back into their original position, causing the occasional Earthquake in the process.

(Top) Simplified diagram showing principle of glacial rebound. Wikipedia. (Bottom) Map showing the rate of glacial rebound in various parts of the UK. Note that some parts of England and Wales show negative values, these areas are being pushed down slightly by uplift in Scotland, as the entire landmass is quite rigid and acts a bit like a see-saw. Climate North East.

Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. If you felt this quake, or were in the area but did not (which is also useful information) then you can report it to the British Geological Survey here.
See also... 2.8 Earthquake in southwest Nottinghamshire.                                                   The British Geological Survey recorded a Magnitude 2.8 Earthquake at a depth of 7 km between Nottingham and Mansfield in southwest Nottinghamhire, England, slightly after 7.15 pm GMT on Tuesday 28 October 2014. An event of this size is highly unlikely to have caused any damage or injuries, but people have reported feeling the event across southwest Nottinghamshire. 1.3 Earthquake in north Nottinghamshire.                                                       The British Geological Survey recorded a Magnitude 1.3 Earthquake at a depth of 1 km in northern Nottinghamshire, England, slightly after 9.30 pm British...
The British Geological Survey recorded a Magnitude 1.4 Earthquake at a depth of 1 km beneath Sherwood Forest in north...
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A new genus of Goblin Spiders from Costa Rica.

In 1938 Jean-Louis Fage of the Muséum National d’Histoire Naturelle de Paris described a new species of Goblin Spider (tiny Spiders generally found living in soil or leaf litter) from a single male specimen from the collection of the Natural History Museum of Vienna as Xestaspis reimoseri, which had apparently been found in a Termite nest in Costa Rica, the only species of Xestaspis ever recorded from the Americas. Since this time the specimen from which Fage described the species has been lost, though the Vienna Museum do still have details of the specimen not provided in Fage’s description, notably the location where it was collected, Hamburg Farm on the banks of the Río Reventazón near Cairo in Limón Province. Hamburg Farm was run by a German entomologist, Ferdinand Nevermann, and after his death the property was acquired by a large Banana company and ceased to exist as a separate property, though a local village still retains the name Hamburg.

In a paper published in the American Museum Novitates on 22 December 2014, Norman Platnick and Lily Berniker of the Division of Invertebrate Zoology at the American Museum of Natural History and Carlos Víquez of the Instituto Nacionalde Biodiversidad in Santo Domingo, Costa Rica, describe a series of specimens from trees at Estación Biológica La Selva in Heredia Province, which they believe to be the same species as Fage’s specimen. They move the species to a new genus, Hexapopha, meaning ‘Six-eyes’ and also implying a similarity to Coxapopha, and describe three further species from Costa Rica, which they also place in this new genus.

The new specimens of Hexapopha reimoseri are a female found in a tree hole with large Ants, a male collected from epiphytic root fibres (i.e. roots produced in the canopy by plants living on branches, to absorb moisture from the air), two males collected from a Virola koschnyi tree (Wild Nutmeg) by fogging (spraying a tree with insecticide and seeing what drops out), and a male collected from by the Camino Experimental Sur 830 m altitude marker. The males average 1.54 mm in length, the females 1.83 mm. Based upon these specimens, it is considered that the species is arboreal in nature (tree dwelling), rather than ground dwelling, and that Fage’s specimen probably came from a tree-living Termite nest.

Hexapopha reimoseri, scanning electron microscope image, male in dorsal view. Platnick et al. (2014).

The first new species described is named Hexapopha hone, in reference to the site where the specimens was collected, at Hone Creek in Limón Province. The species is described from two specimens, a male and a female, collected by beating bushes in an abandoned Cacao field on the farm of Alberto Moore. The male is 1.41 mm in length, the female 1.74 mm.

Hexapopha hone, male in (76) dorsal view and (77) lateral view, female in (79) dorsal view and (80) lateral view. Platnick et al. (2014).

The second new species described is named Hexapopha jimenez, after Puerto Jiménez in Puntarenas Province, close to where one of the specimens was collected. The species is described from two female specimens, one from the collection of the Museum of ComparativeZoology at Harvard University, collected from an unknown substrate 13 km to the southwest of Puerto Jiménez, the other from the collection of the Instituto Nacional de Biodiversidad, collected from humus (soil) at an unknown location in Costa Rica. The specimens are 1.74 mm in length.

Hexapopha jimenez, female specimen in dorsal view. Platnick et al. (2014).

The third new species described is named Hexapopha osa, after the Península de Osa in Puntarenas Province, where the specimens from which the species is described were collected. The species is described from two females collected from an unknown substrate at Rancho Quemado, two males collected from humus at Sirena, a female collected from a log at the Tropical Science Center, 5 km  to the west of Rincón de Osa, a male collected from leaf litter on a ridge close to the same log, a male collected from a decomposed log, also at the Tropical Science Center, and two males and a female, collected from a slightly decomposed log at an angle of 45° in a stream bed, also at the Tropical Science Center. The males average 1.69 mm in length and the females 1.87 mm.


Hexapopha osa, male in (111) dorsal view and (112) lateral view, female in (114) dorsal view and (115) lateral view. Platnick et al. (2014).

See also… Spiders from Cretaceous Amber.    Goblin Spiders (Oonopidae) are one of the most abundant groups of Spiders, with at least 600 and possibly over 1000 extant species described, though this is generally considered to be a poor representation of their diversity, since the Spiders are tiny (often unde...
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Wednesday, 28 January 2015

A new species of Giant Swallowtail Butterfly from North and Central America.

Swallowtails, Papilionidae, are among the most conspicuous of American Butterflies, due to their large size and conspicuous colouration. The group has been extensively studied by taxonomists and evolutionary biologists, revealing a complex biological history, with widespread mimicry leading to a large number of cryptic species (species which resemble one-another closely, making it hard for even specialists to tell them apart) and many species that have apparently arisen through hybridization. However within the group the Tiger Swallowtails, Pterourus spp., have been the most extensively studied, with the related Giant Swallowtails, Heraclides spp., being relatively less well known.

In a paper published in the journal ZooKeys on 23 December 2014, Kojiro Shiraiwa of San Diego in California, Qian Cong of the Departments of Biophysics and Biochemistry at the University of Texas Southwestern Medical Center and Nick Grishin of the Howard Hughes Medical Institute and the Departments of Biophysics and Biochemistry at the University of Texas Southwestern Medical Center, describe a new species of Giant Swallowtail Butterfly from the southwest United States, Mexico and Central America.

The new species is named Heraclides rumiko, in honour of the wife of Kojiro Shiraiwa. The species is not described from any newly discovered populations, but rather the realization that the widespread Heraclides cresphontes, which is known from Canada to Panama, is in fact a complex of (at least) two closely related cryptic species.

Heraclide srumiko type specimens: 7–8 holotype 9–10 paratype. Dorsal/ventral surfaces are in odd/even-numbered figures. Labels areshown between the images of the same specimen, exuvia and head capsules in a gelatin capsule are below,and 3-fold magnified segment of head, neck and thorax is on the left. All images are to scale (includinglabels), except the magnified insets. Shiraiwa et al. (2014).

The discovery came about following an examination of specimens from California and Indiana, which revealed differences in the patterns between the two populations. This was followed by an examination of DNA from specimens from the northeastern United States and Costa Rica, which revealed a 3% difference in genetic structure. This is not in itself enough to justify the erection of a new species, particularly in widespread species where genetic patterns are likely to vary over distance, however it did provoke a wider study in which 200 specimens from across the range of the species were examined, revealing two distinct population groups, separated by a genetic distance of 3%, but with very little difference within populations. Notably in parts of Texas both species were found living alongside one-another, suggesting that these are true species.

Facies differences between Heraclides rumiko (left, r) Heraclides cresphontes (right, c) indicated by red trianglesand lines. These differences are as follows. (1) Dark spot on forewing: (r) almost always large; (c) variable,but often weak and sometimes absent (2) Forewing margin: (r) often straight with smaller or absentmarginal spots; (c) strongly scalloped with yellow marginal spots at dips between veins (3) Forewing submarginalyellow spots: (r) smaller rarely more than three; (c) frequently larger, more than three (4) Thoraxwith: (r) yellow line running from head through patagia to tegulae; (c) spots instead of the line, or just fewyellow scales. (5) Abdomen: (r) usually with a fainter dark band; (c) often with solid dark band (6) Inneredge of black discal band on ventral hindwing: (r) mostly straight; (c) usually curved (7) Tail: (r) mostlynarrow and relatively longer; (c) typically rounder and wide, shorter. Heraclides rumikois usually smaller than Heraclides cresphontes, despite being a southern taxon. Due to significant seasonal and individual variation, noneof these characters is fully reliable and exceptions exist. The head-neck-thorax line vs. spots might be the strongest single character. A combination of characters should be used for reliable identification. Many specimens in central Texas exhibit intermediate characters, a typical character combinations, and possible hybrids can be found. Shiraiwa et al. (2014).

The original species Heraclides cresphontes is now thought to be found in southeast Canada, and the north and west of the United States, while the new species is found in Texas, New Mexico, Arizona, California and Colorado, plus across Mexico and in El Salvador, Honduras, Costa Rica and Panama, though it is possible that other cryptic species are hidden within these distributions.

Localities of Heraclides cresphontes and Heraclides rumiko specimens with available DNA barcode information. Colour of circles corresponds to species: Heraclides cresphontes - blue (based on 112 DNA COI barcode sequences, 103 obtained in this work); Heraclides rumiko - red (based on 183 barcodes, 146 obtained in this work), split red/blue circles mark localities where both Heraclides cresphontes and Heraclides rumiko were recorded. Type localities for taxa with available names are indicated with a corresponding name followed by “TL”. Papilio cresphontes var. maxwelli & Papilio cresphontes pennsylvanicus are treated as junior subjective synonyms of Heraclides cresphontes. Countries and states (for USA andMexico) with records are labeled. Shiraiwa et al. (2014).

The eggs of Heraclides rumiko were laid singularly on young leaves of trees and shrubs from the family Rutaceae in California and Texas, the only places where the life-cycle has been observed to date. Host plants included Zanthoxylum fagara, Ptelea trifoliata, Amyris texana, Ruta graveolens, Citrus spp. and Geijera parviflora, and the species probably utilizes other plants that have not been observed. The species is particularly numerous in urban areas where widespread ornamental citruses are planted. The eggs are 1.1–1.6 mm in diameter, round and have a granular surface. They are yellowish when laid, but turn orange as they mature.

Eggs of Heraclides rumiko. Shiraiwa et al. (2014).

The eggs hatch 7-10 days after being laid, the larva eating the egg after hatching. The first instar (an instar is a stage in the life of an Insect, separated from other instars by moults) is 3-5 mm long, hairy, glossy and mottled brown, generally resembling a Bird dropping. The second instar is 5-11 mm long, the third 11-16 mm, the fourth 16-30 mm, the fifth instar 30-50 mm. The fifth instar is matt rather than glossy in appearance, and is followed by pupation. Under ideal conditions the caterpillar can progress from hatching to pupation in about nine days.

Fifth instar caterpillars of Heraclides rumiko. Shiraiwa et al. (2014).

While the caterpillars of Heraclides rumiko are primarily protected by camouflage, resembling a Bird dropping, they also have a pair of eyespots on their meta-thoraxes, which can be revealed suddenly by raising the head and inflating the thorax, a defensive strategy employed when the caterpillar is startled.

Defensive posture of a caterpillar of Heraclides rumiko. Shiraiwa et al. (2014).
Towards the end of its fifth instar the caterpillar changes colour, becoming paler and more uniform. This apparently improves the camoflage as it leaves the leafy parts of the plant and travels on woody branches, looking for a suitable place to pupate. The pupae are 26-36 mm in length, and mottled greyish or dark brown, mimicking the colour of the branch on which they rest to some extent (i.e. pupae on greenish branches are greener, on dark-coloured branches are darker, etc.). Adults can emerge in one to two weeks, but the pupae can also act as the overwintering stage, going into diapause (hybernation) for several months.

Pupae of Heraclides rumiko on different coloured stems. Shiraiwa et al. (2014).

Adults of Heraclides rumiko are present throughout most of the year, being absent only in the coldest months. In southern Texas they are seen on the wing from April till September, going through emergence peaks every 1.5 months, though this can be affected by the severity of the winter or variations in rainfall. In southern California the adults are present from February till mid November, being most abundant in August and September.

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