The stratigraphy, palaeoecology and palaeobiogeography are outlined for two genera and ten species of Jurassic planktonic foraminifera described in Gradstein et al. (Swiss J Palaeontol 2017 . doi: 10.1007/s13358-017-0131-z ). The two genera are Globuligerina and Conoglobigerina. Globuligerina probably appeared in late Toarcian (late Early Jurassic) and Conoglobigerina first occurred in Middle Oxfordian (early Late Jurassic). Within the two genera ten species are defined, including from older to younger: Globuligerina dagestanica (Morozova), G. avariformis (Kasimova), G. balakhmatovae (Morozova), G. oxfordiana (Grigelis), G. bathoniana (Pazdrowa), G. jurassica (Hofman), G. oxfordiana (Grigelis) calloviensis Kuznetsova emended, G. tojeiraensis Gradstein, Conoglobigerina helvetojurassica (Haeusler), C. grigelisi Gradstein and C. gulekhensis (Gorbachik and Poroshina). Globuligerina balakhmatovae, G. oxfordiana and G. bathoniana are longer ranging, although there are subtle evolutionary trends in these taxa that may refine stratigraphic usage. Other taxa have shorter stratigraphic ranges. Using stratigraphic trends, test morphology and wall texture changes, the species are tentatively assembled in four evolutionary groups, termed A–D, and in six zones from Late Toarcian through Tithonian. The greater species diversity and possibly also specimen abundance took place in the Kimmeridgian, a time of high global sea level and greenhouse palaeoclimatic conditions. Jurassic planktonic foraminifera preferred marine continental margin conditions instead of the distal open ocean and spread from offshore Eastern Canada to offshore Western Australia along the margins of the Tethys Ocean. The group did not venture into austral or boreal realms, likely reasons why migration probably failed to the west coasts of South and North America.

The taxonomy is modernized and updated for Jurassic planktonic foraminifera using all available literature and stratigraphic series of sediment samples from Canada, Portugal, France, Switzerland, Poland, Lithuania, Russia and Dagestan. The regional stratigraphy of all sampled sections is outlined. Many of the 65–200 µm sample residues yielded well-preserved free specimens, with local assemblages containing up to six species. Thin sections were studied also but do not allow detailed taxonomy. Two genera are described: Globuligerina and Conoglobigerina. Globuligerina probably appeared in the late Toarcian (late Early Jurassic) and Conoglobigerina first occurred in middle Oxfordian (early Late Jurassic). A principal difference between Globuligerina and Conoglobigerina is that the former has a smooth to pustulose wall surface texture and the latter a reticulate wall surface texture. Within the two genera, ten species are described, including from older to younger: Globuligerina dagestanica (Morozova), G. avariformis (Kasimova), G. balakhmatovae (Morozova), G. oxfordiana (Grigelis), G. bathoniana (Pazdrowa), G. jurassica (Hofman), G. oxfordiana (Grigelis) calloviensis Kuznetsova emended, G. tojeiraensis Gradstein, Conoglobigerina helvetojurassica (Haeusler), C. grigelisi Gradstein and C. gulekhensis (Gorbachik and Poroshina). The coarsely perforate ‘Globuligerina’ stellapolaris needs more investigation to establish its identity as a Jurassic or a Late Cenozoic taxon (Gradstein 2017a ). Globuligerina balakhmatovae, G. oxfordiana and G. bathoniana occur from Bajocian through early Kimmeridgian, or even Tithonian. Subtle morphological trends may refine stratigraphic usage. Other taxa have shorter stratigraphic ranges. Nineteen plates and ten type species figures detail morphology of all taxa. For key taxa, both the types and specimens from other localities are illustrated.

Two Jurassic planktonic genera are emended and two new species and one subspecies of Jurassic planktonic foraminifera are defined. The genera are Globuligerina Bignot and Guyader 1971 and Conoglobigerina Morozova 1961 and the two new species are Globuligerina tojeiraensis Gradstein and Conoglobigerina grigelisi Gradstein. Both new species commonly occur in the Tojeira Formation, Montejunto, Portugal. The Tojeira Formation is a deeper marine shale unit of Early Kimmeridgian age. The new subspecies is Globuligerina oxfordiana calloviensis Gradstein, from the Callovian in the Crimea and Ukraine. A detailed description is provided for one of the historically oldest Jurassic taxa, Conoglobigerina helvetojurassica Haeusler 1881, re-discovered in the Birmenstorfer Schichten of Middle Oxfordian age near Mönthal, Canton Aargau, Switzerland. A neotype is proposed for this taxon. One specimen of C. helvetojurassica may have been attached to a substrate during a later part of its life cycle. The same Birmenstorfer Schichten also yielded two small specimens of an unknown planktonic genus with longitudinal ribs along its pyramidal and probably triserial test. The test is microperforate and wall textures reticulate. The types and type locality of ‘Globuligerina’ stellapolaris Grigelis, described from Northwestern Russia should be carefully investigated, to determine if it is a Late Jurassic or a Late Cenozoic taxon.

Globuligerina glinskikhae nov. sp. Gradstein & Waskowska and Globuligerina waskowskae nov. sp. Gradstein are new species of Jurassic planktonic foraminifera from the Middle Jurassic of Dagestan and Poland. G. glinskikhae nov. sp. with its remarkable ‘protoglobigerine’ test may be an early evolutionary offshoot of Globuligerina oxfordiana (Grigelis). It may be an index taxon for upper Bajocian through Bathonian strata in Eastern Europe and Southwest Asia, and might be recognizable also in thin sections. We consider G. waskowskae nov. sp. to be a possible forerunner of Conoglobigerina helvetojurassica (Haeusler), the first planktonic foraminiferal species with a reticulate wall texture. Currently, is only known from Poland. In some localities, specimens of G. oxfordiana and of G. glinskikhae nov. sp. posses an additional apertural opening, often lacking a rim; its function is enigmatic. The postulated lineage from Jurassic Globuligerina balakhmatovae (Morozova) to Cretaceous Clavihedbergella eocretacea Neagu is refined with the description of Petaloglobigerina simmonsi nov. gen., nov. sp. Gradstein from the Kimmeridgian of Portugal. The evolutionary transition from G. balakhmatovae to P. simmonsi occurs by means of the ontogenic development of a petaloid test, with a pronounced flattening of the whorl with ovate chambers, the last ones often offset and twisted. Jurassic planktonic foraminifera, now known to consist of three genera and 12+ species underwent long periods of stasis, interrupted by late Bajocian, mid-Oxfordian and early Kimmeridgian evolution. The three ‘stasis and root’ taxa G. oxfordiana , G. bathoniana and G. balakhmat ovae are geographically widespread in lower to mid palaeo-latitudes, and stratigraphically long ranging within the Middle and Late Jurassic. Modern digital microscopes, with co-axial and side LED lighting and excellent image stacking software are important tools in the study of Jurassic planktonic foraminifera, and fast and cost-effective communication tools in modern micropalaeontology. ZooBank LSID: urn:lsid:zoobank.org:pub:A2927FFD-8C2B-4712-A06F-EE9D45ACA481.

We provide a biochronology of Jurassic planktonic foramininfera, using first order linkage to ammonite and nannofossil stratigraphy and geochronology. This enigmatic and understudied group of microfossils occurred from middle Toarcian through Tithonian time, from ~180 to ~143 Ma; its origin is unknown. There are three genera: Globuligerina, Conoglobigerina and Petaloglobigerina. The genus Globuligerina, with a smooth to pustulose test surface texture appeared in Toarcian (late Early Jurassic) and Conoglobigerina, with a rough reticulate test surface texture in Oxfordian (early Late Jurassic) time. The genus Petaloglobigerina, having a petaloid last whorl with one or more claviform and twisted chambers evolved in early Kimmeridgian time from Globuligerina balakhmatovae. Biochronologic events for Jurassic planktonic foraminifera are most like First Common Appearance or Last Common Appearance events. The very first or very last appearance levels of taxa are not easily sampled and detected. We recognize stratigraphic events from eleven species across four postulated evolutionary lineages, calibrated to Geologic Time Scale 2020. A faunal change, which is not well documented led to the survival of only one taxon, most likely Gobuligerina oxfordiana in the Tithonian.