Mesozoic Spiders Beitr

Mesozoic Spiders Beitr

MESOZOIC SPIDERS BEITR. ARANEOL., 9 (2015) BEITR. ARANEOL., 9 (2015) Joerg Wunderlich (ed.) SPINNEN DES ERDMITTELALTERS (2015) 9 Joerg Wunderlich (ed.) We do not have a time machine to look backwards on earth but we have fossils which can tell us something about life millions of years ago. In this volume different aspects of spider evolution are treated, and a provisional detailed over- view over the Mesozoic fauna of one of the most diverse “megaorders” of arthropods – the spiders (Araneae) – is given for the first time. Based mainly on fossils from Myanmar (Burma) it includes a list and provides keys to the taxa known up to the beginning of 2015, which are documented by numerous coloured photos and drawings. Certain behavioural, biogeographical, ecological and BEITR. ARANEOL., Joerg Wunderlich (ed.) phylogenetic aspects are also treated. Few papers by other authors are included in this volume. Today the amber from Myanmar (Burmite) represents the most important and fascinating “win- dow” to Cretaceous arthropods. The study of the 100 million year old fossil spiders provides a tiny puzzle piece to reconstruct a small part of a fascinating and strange vanished world. The enigma of the first spiders (Araneae): How many million years ago did animals of this order exist? What did they look like at the beginning in the Palaeozoicum? Which important new char- acters – innovations – did spiders evolve during their existence of 400 million years? Did the first spiders already have poison glands and build capture webs similar to today’s spiders? Hopefully, in Cretaceous resins we will find the roots of diverse “modern” spider families like Jumping spi- ders (Salticidae), Daddy-long-legs Spiders (Pholcidae), Wolf Spiders (Lycosidae) and Crab Spiders (Thomisidae) which are all unknown from the whole Mesozoic period like the whole very diverse spider branch of the Dionycha. The faunas of ancient spiders (Araneae): How was the spider fauna composed in the middle ages of the Earth (the Mesozoicum)? The order of spiders is one of the largest and most diverse orders of animals on Earth; I assume that several hundred thousand living and extinct species altogether MESOZOIC SPIDERS exist (more than 42000 species are known today, about 1200 fossil species). Thanks to the fre- quently excellent preservation (see the photos!), and the intensive studies of fossils during the SPINNEN DES ERDMITTELALTERS last decade the spider faunas of the Cretaceous (65 to 145 million years ago) – the main age of the Dinosaurs! – supplies a surprising insight into selected ancient spider faunas of the Northern Hemisphere, which are quite strange compared to faunas of today, and which consist predomi- nantly of ancient and even extinct families. Orders of this book directly to the author: Other books by the same E-mail: [email protected] see the website: www.joergwunderlich.de Publishing House Joerg Wunderlich Oberer Haeuselbergweg 24 69493 Hirschberg Germany MESOZOIC SPIDERS SPINNEN DES ERDMITTELALTERS ISBN 978-3-931473-15-2 BEITR. ARANEOL., 9 (2015) BEITRÄGE ZUR ARANEOLOGIE, 9 (2015) ISBN 978-3-931473-15-2 MESOZOIC SPIDERS (ARANEAE) ANCIENT SPIDER FAUNAS AND SPIDER EVOLUTION PAPERS ON FOSSIL AND EXTANT ARANEAE AS WELL AS FOSSIL AMBLYPYGI, RICINULEI, SCORPIONES AND UROPYGI SPINNEN DES ERDMITTELALTERS FOSSILE SPINNENFAUNEN UND DIE EVOLUTION DER SPINNEN ARBEITEN ÜBER FOSSILE UND HEUTIGE SPINNEN SOWIE FOSSILE GEISSELSPINNEN, KAPUZENSPINNEN, SKORPIONE UND GEISSELSKORPIONE JOERG WUNDERLICH (ed.) 1 BEITR. ARANEOL., 9 (2015) The photos on the book cover show Mesozoic spiders in Burmese amber of the Mid Cretaceous: AT THE TOP LEFT: Male of the ancient family Psilodercidae, Leclercera ellenbergeri n. sp., body length 1.4 mm. Note the quite long and thin legs of this excellently preserved male! AT THE TOP RIGHT: Female of the extinct family Lagonomegopidae, Picturmegops sig- natus n. gen. n. sp., body length 3.6 mm. Note the excellently preserved distinctive colour pattern on the prosoma and on the opisthosoma which is caused by hairs! This colouration had probably two different functions, see the family below. IN THE MIDDLE LEFT: Female of the ancient family Archaeidae, Burmesarchaea grimal- dii (PENNEY 2003), body length 2.8 mm. Note the special position of the chelicerae, the scutate body and the opisthosomal furrows! IN THE MIDDLE RIGHT: Male of the extinct family Lagonomegopidae, Lineaburmops hirsutipes n. gen. n. sp., body length 5 mm. The peculiar extinct spider family Lag- onomegopidae was very diverse in genera and in the shape and the colour as well as in other characters in the age of the dinosaurs during at least 70 million years in the Cretaceous. Note the beautiful preserved bands of white hairs on the prosoma! AT THE BOTTOM LEFT: Male of the family Uloboridae, Paramiagrammopes patellidens n. sp., body length 2.2 mm, the member of an extinct genus. All genera shown on this cover are extinct). See also the next page: the cover photo AT THE BOTTOM RIGHT! 2 BEITR. ARANEOL., 9 (2015) The fossil spider of the year 2015 (selected by the editor and friends): This peculiar male fossil spider, dorsal aspect, body length only 2.8 mm, lived 100 million years ago in a rain forest of Myanmar (Burma). It is first described in this volume as Burmadictyna excavata of the extinct Cretaceous family Sal- ticoididae, a group of orb-web weaving spiders. What is unique in this spider species? From certain structures of the male copulatory organ we can conclude a special mating behaviour of this species which is known to be similar in some spiders of today. This behaviour concerns the most important part of the male copularory organ, the EMBOLUS of the pedipalpus (see the drawing above) which has the main function of a penis: it transfers the sperm to the female copulatory organ. The embolus of this fossil male has quite an unusual structure: (a) It is coiled in 12 loops of spirals which build a long cylinder. I estimate that this genital part repre- sents 3.5 (!) times the length of the spider’s body. No one knows the reason for the evolution of such a long introductory structure of the male genital organ, and how it was used by the spider! (b) The apical part of the embolus (arrow in the drawing) is strongly modified and widened, bearing barbs in a harpoon-shaped structure. It has a basal constriction, which I regard to be connected with a breaking line in this area. – What about the function of this structure? Male spiders of several families of today – frequent are orb weavers – are known to possess a very special behaviour in connection with a peculiar part of their embolus: A part of this copulatory organ breaks off and is left within the genital duct of the female after copulation. Such a „mating plug“ is considered to prevent the intromission of sperm by other males, to secure the development of off- springs only of its own. Furthermore it is a peculiar case of GENITAL SELF-MUTILATION, and the same pedipalpus is probably not usable for a further copulation. Such structures exist at the end of both emboli in all the three known fossil males of this genus; so we may conlude that none of them did have sex. The present male (photo) is the first proof of such a behaviour in fossil spiders. It demon- strates that the use of mating plugs is a very old behaviour in spiders, dating back at least 100 million years. –The spider is described p. 314-317. 3 BEITR. ARANEOL., 9 (2015) ISBN 978-3-931473-15-2 MESOZOIC SPIDERS (ARANEAE) ANCIENT SPIDER FAUNAS AND SPIDER EVOLUTION PAPERS ON FOSSIL AND EXTANT ARANEAE AS WELL AS FOSSIL AMBLYPYGI, RICINULEI, SCORPIONES AND UROPYGI SPINNEN DES ERDMITTELALTERS FOSSILE SPINNENFAUNEN UND DIE EVOLUTION DER SPINNEN ARBEITEN ÜBER FOSSILE UND HEUTIGE SPINNEN SOWIE FOSSILE GEISSELSPINNEN, KAPUZENSPINNEN, SKORPIONE UND GEISSELSKORPIONE JOERG WUNDERLICH (ed.) Editor and author of most papers as well: Joerg Wunderlich © Publishing House: Joerg Wunderlich, 69493 Hirschberg, Germany Print: M + M Druck GmbH, Heidelberg. Orders for this volume: Publishing House Joerg Wunderlich Oberer Haeuselbergweg 24 69493 Hirschberg Germany E-Mail:[email protected] Web site (including other books by JW): www.joergwunderlich.de 4 BEITR. ARANEOL., 9 (2015) CONTENTS page WUNDERLICH, J.: Description of an unusual fossil Crab Spider (Araneae: Thomisidae s. l.: Stephanopinae) in Eocene Baltic amber . 7 WUNDERLICH, J.: „Frozen behaviour“: The oldest fossil proofs of spider eating spiders (Araneae) in 45 million years old Eocene Baltic amber and in 100 million years old Cretaceous amber from Myanmar (Burma). 15 WUNDERLICH, J.: ON THE EVOLUTION AND THE CLASSIFICATION OF SPIDERS, THE MESOZOIC SPIDER FAUNAS, AND DESCRIPTIONS OF NEW CRETACEOUS TAXA MAINLY IN AMBER FROM MYANMAR (BURMA) (ARACHNIDA: ARANEAE). 21 WUNDERLICH, J.: New and rare Arachnida in Cretaceous Burmese amber (Amblypygi, Ricinulei and Uropygi: Thelephonida) . 409 WUNDERLICH, J.: Descriptions of the new subgenera Parvidipoena and Simonola of the genus Lasaeola SIMON 1881 s. l. which include two tiny European species (Araneae: Theridiidae). 437 WUNDERLICH, J.: Desription of two Gnaphosidae (Araneae) from Portugal: Phaeocedus mikha LEVY 2009 new to Europe, and Gnaphosa monteserra n. sp. 446 WUNDERLICH, J.: Additions and correction concerning vol. 7 of the Beitr. Araneol. (2012): Fifteen papers on extant and fossil spiders (Araneae). 450 WUNDERLICH, J.: Corrections concerning vol. 8 of the Beitr. Araneol. (2012): The Spider Families of Europe by J. WUNDERLICH. .451 TANASEVITCH, A. V. & WUNDERLICH, J.: A new Megalepthyphantes WUNDERLICH, 1994 (Araneae: Linyphiidae) from a cave of Crete (Greece). .452 WUNDERLICH, J.: Glosse: Pfui Spinne – Linguistische Gendereien. 456 LOURENÇO, W. R.: A new subfamily, genus and species of fossil Scorpions from Cretaceous Burmese amber (Scorpiones: Palaeoeuscorpiidae). 457 LOURENÇO, W. R.: Clarification of the familiar status of the genus Palaeoburmesebuthus LOURENÇO, 2002 from Cretaceous Burmese amber (Scorpiones: Archaeobuthidae: Palaeoburmesebuthinae).

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