01820nas a2200145 4500008004100000022001400041245009400055210006900149260001600218520131700234100001601551700001601567700002101583856007001604 2021 eng d a0031-022000aA new look at Eccaparadoxides (Cambrian, Trilobita) and its biostratigraphic significance0 anew look at Eccaparadoxides Cambrian Trilobita and its biostrati cOct-12-20213 a

Eccaparadoxides is a geographically widely distributed trilobite genus that occurs in the middle part of the Cambrian System. However, the systematically important morphologic characteristics that can be used to differentiate taxa are often problematical in their application. A review of the large number (over 30) of significant species or forms assigned to Eccaparadoxides clearly indicates that only the pygidia offer fairly reliable morphologic criteria that can be used taxonomically and phylogenetically. The pygidia allow for recognition of four different morphological groups (pusillus, lamellatus, pradoanus and asturianus) of which the asturianus group can only be questionably assigned to the genus. Species known only from cranidia cannot be assigned to Eccaparadoxides with certainty. This study refines the biostratigraphy for the interval from the upper Wuliuan to the middle Drumian and shows that this interval brackets the range of most Eccaparadoxides species. The genera or subgenera Baltoparadoxides, Rejkocephalus and Macrocerca are evaluated. Eccaparadoxides zelus, E. epimetheus and Eccaparadoxides? hestia are newly proposed species.

1 aGeyer, Gerd1 aLanding, E.1 aŻylińska, Anna uhttps://link.springer.com/article/10.1007/s12542-021-00580-9#Abs101396nas a2200145 4500008004100000245011900041210007000160260001600230300000900246490000700255520089800262100001601160700001601176856005801192 2021 eng d00aThe Souss lagerstätte of the Anti-Atlas, Morocco: discovery of the first Cambrian fossil lagerstätte from Africa0 aSouss lagerstätte of the AntiAtlas Morocco discovery of the firs cJan-12-2021 a31070 v113 a

Episodic low oxygenated conditions on the sea-floor are likely responsible for exceptional preservation of animal remains in the upper Amouslek Formation (lower Cambrian, Stage 3) on the northern slope of the western Anti-Atlas, Morocco. This stratigraphic interval has yielded trilobite, brachiopod, and hyolith fossils with preserved soft parts, including some of the oldest known trilobite guts. The “Souss fossil lagerstätte” (newly proposed designation) represents the first Cambrian fossil lagerstätte in Cambrian strata known from Africa and is one of the oldest trilobite-bearing fossil lagerstätten on Earth. Inter-regional correlation of the Souss fossil lagerstätte in West Gondwana suggests its development during an interval of high eustatic levels recorded by dark shales that occur in informal upper Cambrian Series 2 in Siberia, South China, and East Gondwana.

1 aGeyer, Gerd1 aLanding, E. uhttp://www.nature.com/articles/s41598-021-82546-0.pdf03029nas a2200241 4500008004100000022001300041245014900054210006900203260001200272300001100284490000800295520225200303653002102555653002002576653001302596653002502609653002202634653001402656653001802670100001602688700001602704856006702720 2020 eng d a1464343X00aCambrian deposition in northwestern Africa: Relationship of Tamlelt massif (Moroccan‒Algerian border region) succession to the Moroccan Meseta0 aCambrian deposition in northwestern Africa Relationship of Tamle c03/2020 a1037720 v1653 a

The Tamlelt massif is physiographically grouped as a continuation of the easternmost High Atlas. However, re-examination of the Tamlelt's Cambrian litho- and biostratigraphy shows a depositional history that differs from that of the Souss Basin to the southwest (i.e., west-central High Atlas and eastern Anti-Atlas of Morocco). Our re-examination leads to recommendations on the local stratigraphic succession and nomenclature. Trilobites from the Al Hamrat Formation in the Tamlelt massif indicate late early Cambrian (upper Epoch 2) siliciclastics overlying shallow marine, carbonate-rich deposits (Jbel Menhouhou Formation) similar to and coeval with those of the distant western Anti-Atlas region but older than and lithologically distinct from fluviatile siliciclastics (Epoch 3) in the nearby eastern Anti-Atlas. The Jbel Menhouhou carbonates unconformably overlie probable terminal Proterozoic volcanics and clastics of the Bou Kaïs Formation (new) and are overlain by shales and arenites of the upper Kheneg El Kahal Group, which features a Cambrian Stage 4 regressive half-cycle. Regional differences in lithofacies disappear in the early Miaolingian with relatively monotonous, mudstone-rich facies in the Tamlelt massif area (Batene El Jdari Formation) comparable to those of the Jbel Wawrmast Formation of the west-central High Atlas and central‒eastern Anti-Atlas. Probable early late Cambrian brachiopods from siliciclastic rocks of the Tamlelt area indicate a later Cambrian depositional history similar to that of the Anti-Atlas and perhaps Moroccan Meseta. The distinctiveness of the upper lower Cambrian deposits of the Souss Basin from those of the Tamlelt massif apparently reflects a depositional framework independent from other regions of the Atlas ranges, and suggests the Tamlelt region was confluent with the Meseta basin to the northwest. Known trilobites permit precise age assignments through the Tamlelt succession and include species (or forms) which contribute to a refined correlation within West Gondwana and improve West Gondwana‒Baltica correlation. The new trilobite species Saukianda? (Saukianda?) dresnayi is proposed.

10aBaltica Avalonia10aBiostratigraphy10aCambrian10aDepositional history10alithostratigraphy10aTrilobita10aWest Gondwana1 aGeyer, Gerd1 aLanding, E. uhttps://linkinghub.elsevier.com/retrieve/pii/S1464343X20300236