CONTRIBUTION TO THE SPIDER (ARANEIDA: ARANEAE AND CHIMERARACHNIDA) FAUA IN UPPER (MID) CRETACEOUS BURMESE (KACHIN) AMBER.

The following spider taxa (order Araneida) in Upper (Mid) Cretaceous Burmese (Kachin) amber (Burmite), 100-110 million years old, are described: (1) Suborder CHIMERARACHNIDA: Chimerarachnidae: Chimerarachne patrickmueller n. sp., C. alexbeigel n. sp. and C. spiniflagellum n. sp.; (2) Suborder ARANEAE: Scytodidae: ?Scytodes nonalta n. sp.; Tetrablemmidae: Electroblemma retroflectum n. sp., Kachinblemma constrictum n. gen. n. sp.; Uloboridae: Parakachin pectunculus n. gen. n. sp.; Protoaraneoididae: Spinipalpitibia occulta n. sp.; Megasetidae: Parvimegasetae araneoidea n. gen. n. sp.; ?Mysmenidae: Myanmarmysmena grandipalpus n. gen. n. sp.; Nanoaenigmatidae n. fam.: Nanoaenigma pumilio n. gen. n. sp.; Zarqaraneidae: Curvitibia pellucidus n. sp., ?Cornicaraneus unuspedipalpus n. sp., Gibberaraneoid furcula n. gen. n. sp. - Parachimerarachne WUNDERLICH 2022 is regarded as a junior synonym of Chimerarachne WANG et al. (2018) (n. syn.). Ideas regarding phylogeny and relationships of the suborder Chimerarachnida - including a revised diagnosis and the new term METACYMBIUM -, as well as of the high taxa Araneae, Araneida, Araneoidea and the symphytognathidan branch are presented. - The Cretaceous taxa represent a remarkable and unique MIX OF TAXA PRESERVED IN AMBER OF THE SAME DEPOSIT: (1) Both suborders of spiders (Araneae and Chimerarachnida), (2) the high branches Mesothelae, Mygalomorpha and Araneomorpha, and (3) ancestors of the RTA-clade as well as members of the very large branches Araneoidea, Deinopoidea and Synspermiata. - The present fossils offer keys (a) to the phylogeny of spiders (Araneida), and (b) to the knowledge of the origin(s) of the orb web; see the paper on extant spiders of the Algarve in this volume. [ABSTRACT FROM AUTHOR]