The Cambrian trilobites of Jordan – taxonomy, systematic and stratigraphic significance

Abstract

Elicki, O. and Geyer, G. 2013. The Cambrian trilobites of Jordan - taxonomy, systematic and stratigraphic significance. Acta Geologica Polonica, 63(1), 1-56. Warszawa. Marine carbonates and siliciclastic rocks of the Burj Formation in Jordan include paucispecific trilobite associations of the (traditional) Lower-Middle Cambrian boundary interval. Comprehensive new material of these trilobites allows a review of their taxonomy and systematic positions as well as a refined morphological description and a reconsideration of previous interpretations of their stratigraphic position and thus the correlation of the fossiliferous beds. In addition to the classic species Kingaspis campbelli (King, 1923) and Redlichops blanckenhorni Richter and Richter, 1941, Timnaella? orientalis (Picard, 1942) and Hesa problematica Richter and Richter, 1941, the discussed trilobites include Issalia gen. nov. with Issalia scutalis gen. nov., sp. nov., Tayanaspis gen. nov. with Tayanaspis bulbosus gen. nov., sp. nov., Uhaymiria gen. nov. with Uhaymiria glabra gen. nov., sp. nov., Cambrunicornia ? jafnaensis sp. nov., Myopsolenites palmeri (Parnes, 1971), M. hyperion sp. nov., and Enixus cf. antiquus (Chernysheva, 1956). Myopsolenites boutiouiti Geyer and Landing, 2004 is now regarded as a junior synonym of Myopsolenites altus (Linan and Gozalo, 1986). A detailed discussion of the correlation with a focus on global aspects provides clues for the utility of potential index fossils for the global Cambrian Series 3 and Stage 5.

Cambrian trilobites from the Huérmeda Formation (Iberian Chains, north‐east Spain) and the inadequacy of the Marianian Stage

“…Rushton & Powell () illustrated one librigena and one well‐preserved pygidium from King's () locality, Wadi Rimeileh (= Wadi At Tayan after Rushton & Powell (), in Jordan), and stated that the poorly‐preserved topotypes make it ‘difficult to ascertain the characters of the species’. In contrast, Elicki & Geyer () assigned some disarticulated sclerites preserved in limestones from Wadi Uhaymir (Jordan) to M. palmeri . Despite the apparent lack of differences between the type material (from Har'Amran, Israel) and the Jordan material described by Elicki & Geyer (), some distinct differences can be pointed out, such as: (1) the length of the posterior branch of the facial suture (ε–ω), longer than the posterior border in the former, and close to zero in the latter; (2) the presence vs absence of a macropleural eleventh (tenth?)…”

“…In contrast, Elicki & Geyer () assigned some disarticulated sclerites preserved in limestones from Wadi Uhaymir (Jordan) to M. palmeri . Despite the apparent lack of differences between the type material (from Har'Amran, Israel) and the Jordan material described by Elicki & Geyer (), some distinct differences can be pointed out, such as: (1) the length of the posterior branch of the facial suture (ε–ω), longer than the posterior border in the former, and close to zero in the latter; (2) the presence vs absence of a macropleural eleventh (tenth?) thoracic segment; (3) the presence of 3 (4?)…”

“…; Webster ). Elicki & Geyer () insisted on the inclusion of Onaraspis in the bathynotids; they considered the hypostomal character to be significant enough to group several genera in this family but neglected the thoracic differences after concluding that the bathynotids, metadoxidids and saukiandids share ‘13 thoracic segments with the 11th segment being macrospinose’ (p. 33), which is incorrect.…”

“…Until better topotypes are described and illustrated from Har ‘Amran (southern Israel) we suggest maintaining the type species for the poorly preserved material sampled in the type area, and erecting Onaraspis geyeri sp. nov. for the material assigned to Myopsolenites palmeri (Parnes, ) by Elicki & Geyer (, holotype: FG602‐021h, adult cranidium). According to Geyer & Landing (), Żylińska & Masiak () and Elicki & Geyer (), other species assigned to Myopsolenites are M. kielcensis (Bednarczyk, ), M. altus (Liñán & Gozalo, ; a senior synonym of M. boutouti Geyer & Landing, ) and M. hyperion Elicki & Geyer, .…”

The ontogeny ofEllipsocephalus(Trilobita) and systematic position of Ellipsocephalidae

“…TRILOBITES of Ellipsocephalidae Matthew, 1887 are important and widely distributed faunal components of Cambrian Series 2 and 3 strata (e.g., Ahlberg & Bergström 1978, Geyer 1990, Westrop & Landing 2000, Elicki & Geyer 2013, Żylińska 2013a. However, the systematic position of this family remains a subject of discussion.…”