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Marginal-marine to non-marine ostracod assemblages from the Bajocian (Mid-Jurassic) of southern Tunisia, precisely from the Krachoua Formation at the Kef El Anneba section near the Beni Kheddache area, are here described and tested for their utility to improve the stratigraphic accuracy and palaeoenvironmental reconstructions. This particular microfauna consists of 11 species belonging to 6 genera and represents 2 distinct types of species-rich assemblages from this time interval, allowing the interpretation of the depositional setting of the fossiliferous horizon from which the samples derive. The first ostracod assemblage is mainly composed of the brackish to shallow marine species Fastigatocythere sp. Mette, 1995; Vernoniella aff. V. bajociana Bate, 1965b; Paracypris sp. A, Paracypris sp. B, Fabanella sarda Malz et al., 1985; Marslatourella aff. M. bathonica Andreu, 1999; and Fabanella aff. F. bathonica Oertli, 1957. This ostracod biofacies reflects marginal marine (shallow platform, restricted lagoon) conditions in the studied area. In contrast, the second ostracod assemblage is exclusively dominated by the non-marine limnic species Alicenula sp., Theriosynoecum pusilla Rohr, 1976; Theriosynoecum aff. T. aveyronensis Rohr, 1976; and Theriosynoecum sp. Such ostracod biofacies reflects the establishment of (a) permanent freshwater lake(s) in the studied area, triggered by the total emersion of the Bajocian Krachoua platform, presumably as response to the short-term sea-level fall event JBj3 of Haq (2017). The recognized ostracod species from the upper part of the Krachoua Formation at Kef El Anneba section (Medenine area) are particularly similar to those already described from the neighbouring sections of Kezzani (Dhaher area) and Krachoua (Tataouine area), facilitating a stratigraphic calibration of the Krachoua Formation, as well as regional correlations of the respective Bajocian continental event within the southern Tunisian palaeogeographic domain. Moreover, the biogeography of the studied ostracod microfauna from the Mid-Jurassic of southern Tunisia provides further arguments to support the hypothesis of significant biological exchanges between Laurasian and Gondwanan islands, as recently demonstrated by means of a charophyte microflora, indicating that Peri-Tethyan biogeography remained relatively uniform during that time interval and challenging the previous assumption of their endemism.

Four sediment cores, drilled at Younga and Ouadrane Sebkhas (Hachichina wetland), were selected for micropalaeontological, sedimentological, geochronological and geochemical investigation coupled to hierarchical cluster and correspondence analysis. Our research aimed at reconstructing the past biodiversity, the Holocene palaeoenvironmental evolution and the responsible forcing. Subsurface sediments record four major phases: i) the first one is characterized by poorly to very poorly sorted silts, the dominance of the lagoonal/estuarine ostracod and the lagoonal/marine foraminifera and high values of terrestrial geochemical element ratios, such as K/Al and Fe/Al, which indicate an estuarine lagoon; ii) two major marine transgressions, TR1 and TR2, allowing the settlement of widely opened lagoons towards 7160-8680 and 5070-5520 cal yr BP, are marked by the enhancement of the marine/brackish ostracods and marine foraminifera, the improvement of species number, individuals number and H and E index values and of the marine element ratios such as Cl/Al and Sr/Al; iii) the opening of the lagoon is hampered by the action of drift currents allowing the genesis of sand spit and the settlement of a closed lagoon, towards 2610-3610 cal yr BP, characterized by the enhancement of lagoonal/estuarine ostracods and lagoonal/marine foraminifera and the increase of the individuals number; iv) the dominance of the lagoonal/estuarine ostracods and the lagoonal/marine foraminifera and the decline of the species number and density mark a brackish lagoon, also characterized by very poorly sorted silts transported by uniform suspension, which evolves to the actual sebkha. This evolution, within a global climate alteration context, from an estuarine environment to the present sebkha passing by an opened lagoon, is linked to the complex hydrographic setting of the sebkhas and of the Ouadrane Wadi outlet discharging in the Hachichina wetland., Rivista Italiana di Paleontologia e Stratigrafia (Research In Paleontology and Stratigraphy), V. 125 N. 2 (2019)

The micropaleontologic study of the oolitic dolomites from the Fkirine Formation, outcropping along the North-South Axis, allows to characterize the Upper Triassic (Norian?-Rhaetian) in Central Tunisia based on the discovery of Agathammines (Hoyenella inconstans and Agathammina austroalpina) and Aulotortus. This "Rhaetian" benthic foraminiferal assemblage, well known in the Peritethyan areas and locally associated with Gandinella falsofriedli, partially occurs in the type-locality of the Fkirine Formation ("Dorsale Tunisienne") and within the Zerzour Formation from the Saharian Shelf (Jeffara)., Rivista Italiana di Paleontologia e Stratigrafia (Research In Paleontology and Stratigraphy), V. 100, N. 3

Order Podocopida Sars, 1866, Published as part of Zaibi, Chahira, Scharf, Burkhard, Viehberg, Finn Andreas, Keyser, Dietmar & Kamoun, Fekri, 2013, Preliminary report on the living non-marine Ostracoda (Crustacea) from Tunisia with the description of a new Psychrodromus species, pp. 499-516 in Zootaxa 3626 (4) on page 502, DOI: 10.11646/zootaxa.3626.4.5, http://zenodo.org/record/223016

Key to the species of the genus Psychrodromus (after Karanovic 2012, modified) 1. Length of the carapace at most 1.4 mm.................................................................... 2 - Length of carapace more than 1.6 mm..................................................................... 6 2. Posterior seta/claw on the UR with a filamentous tip...................................... P. fontinalis (Wolf, 1920) - Posterior seta/claw on the UR without a filamentous tip....................................................... 3 3. Posterior claw of the UR at the most �� as long as anterior claw.......................... P. turcicus (Hartmann, 1964) - Posterior claw of the UR longer than �� of the anterior claw.................................................... 4 4. Dorsal margin of the carapace only slightly arched, carapace elongated, male clasping organ of maxilliped beside the 2 bristles one respectively two truncated setae......................................................... P. tunisicus n. sp. - Dorsal margin of the carapace distinctly arched, not elongated, male clasping organ without truncated setae............. 5 5. Posterior margin of the carapace broadly rounded, posterior seta/claw on the UR very broad and very slightly narrowing from the basis to the tip....................................................... P. o l iv a c e u s (Brady & Norman, 1889) - Posterior margin of the carapace slightly inclined, posterior seta/claw on the UR very narrow distally...................................................................................... P. betharrami Danielopol & Baltan��s, 1993 6. Dorsal margin highly arched, greatest H in the middle from which point margin slopes equally towards anterior and posterior ends...................................................................... P. peristericus (Petkovski, 1959) - Dorsal margin less arched, greatest H situated around the middle from which point margin inclined towards anterior end and more rounded towards posterior end........................................ P. robertsoni (Brady & Norman, 1889), Published as part of Zaibi, Chahira, Scharf, Burkhard, Viehberg, Finn Andreas, Keyser, Dietmar & Kamoun, Fekri, 2013, Preliminary report on the living non-marine Ostracoda (Crustacea) from Tunisia with the description of a new Psychrodromus species, pp. 499-516 in Zootaxa 3626 (4) on page 507, DOI: 10.11646/zootaxa.3626.4.5, http://zenodo.org/record/223016

Family Cyprididae Baird, 1845, Published as part of Zaibi, Chahira, Scharf, Burkhard, Viehberg, Finn Andreas, Keyser, Dietmar & Kamoun, Fekri, 2013, Preliminary report on the living non-marine Ostracoda (Crustacea) from Tunisia with the description of a new Psychrodromus species, pp. 499-516 in Zootaxa 3626 (4) on page 503, DOI: 10.11646/zootaxa.3626.4.5, http://zenodo.org/record/223016

Infraorder Cypridocopina Jones, 1901

Genus Psychrodromus Danielopol & McKenzie, 1977 Holotype: 1 male. No. K- 42856 - Zoological Museum Hamburg Paratypes: on slides: 1 male, 4 females. No. K- 42857 a-e ��� Zoological Museum Hamburg undissected in ethanol: 5 males, 55 females, and 31 larvae. No. K- 42858 - Zoological Museum Hamburg Type locality: near road P 12 between Kairouan and Maktar, near Kef El Garia tunnel; effluent of a karstic spring, only few meters east of the pond below a waterfall (O- 108 in Fig. 1) (35 �� 46 ��� 14.8 ��� N, 09�� 26 ��� 44.9 ��� E); very low discharge (Fig. 2). Etymology: The new species is named after the country where the animals were found. Material examined: 12 adult males, 76 adult females, and 38 juveniles collected on the 8 th November 2010, leg. B. Scharf and C. Zaibi. Associate fauna: 7 adult and 2 juvenile Darwinula stevensoni. Diagnosis: small Psychrodromus species, carapace elongated, anterior and posterior very broadly rounded, dorsal margin only slightly arched, LV of both sexes with a small inner list, male clasping organs of maxilliped with one, or two additional truncated setae, respectively. Description (Figs. 3���6): Female: Surface of carapace smooth, ventrally white, dorsally green with a transition from white to green, surface ventrally hirsute, valves with conical inclusions (in transmitted light shown as small dark dots, figured on the anterior part of the valves in Fig. 3). Carapace in lateral view: elongated (ratio of height to total length: 0.48���0.52). LV overlaps anteriorly, posteriorly and ventrally RV (Figs. 6 F to J). A small list developed inside on the LV anteriorly, posteriorly, and ventrally, running in parallel to the shell edge, forming a groove between the list and the edge. Dorsal margin of carapace only slightly arched; greatest height of LV posterior, of RV anterior of the middle of the carapace; ventral margin moderate concave. Fused zone anteriorly and posteriorly narrowed, with a large number of slender radial canals, ventrally widened. Calcareous inner lamella of both valves anteriorly wider than posteriorly (ratio of maximal width of inner lamella to total length of carapace: anteriorly 0.17���0.19, posteriorly 0.07���0.09). Carapace in dorsal view: greatest width in the middle, both ends slightly rounded. Dimensions (n= 13): length: 1.16���1.23 mm, height: 0.57���0.62 mm. Antennule, first two segments fused forming a large basis with Rome organ, aesthetasc y a at joint 5. Terminology of the joints according to Boxhall et al. (2010), length of the joint 4 a in relation to the length of the 2 short setae of joint 3 b: 20: 50: 36 (Fig. 4 A). Antenna with very short natatory setae of nearly the same length (relation of the length of the penultimate joint to the length of the natatory setae: 45: 20), length of the claws: G 1: G 2: G 3: GM: Gm = 100: 64: 81: 78: 32 (Fig. 4 B). Mandibule with a masticatory process with strong teeth, a jointed setose palp and a well developed vibratory plate (Fig. 4 D). Food rake with 7 teeth (Fig. 4 E). Maxillule with 2 serrate teeth bristles (Zahnborsten) on third endite and with a slightly spatula-like terminal segment of the palp (Fig. 4 F). Maxilliped L 5 lacks ���c��� bristle on the protopod (Figs. 4 G and H). Walking leg L 6 5 -segmented with a well developed apical claw (Fig. 5 A). Cleaning leg L 7 with a pincer-organ and 1 long seta on penultimate segment at around mid-length (Fig. 4 K). Uropod: Uropodal attachment without Triebel loop, but with basal triangular reinforcement characteristic for the subfamily Herpetocypridinae (Fig. 5 B). Uropodal rami slightly asymmetric, right uropodal ramus forming a simple curve while left uropodal ramus slightly S-shaped; well developed anterior seta, posterior claw of about 60 % of length of anterior claw; posterior seta a truncated spine with few setulae apically; posterior margin of rami with many irregularly set setulae (Figs. 5 B, C, F). Male: Carapace similar to that of female, except in lateral view: here, greatest height of both valves posterior of the middle of the carapace (Figs. 3 A, B and Figs. 6 A to E). Dimensions (n= 9): length: 1.10���1.21 mm, height: 0.56���0.60 mm. Antennule, mandible, walking leg L 6, cleaning leg L 7, and uropod of males are similar to those of the females. Antenna, claw GM at the distal segment is strongly pectinated. Relation of this claw to aesthetasc y 3 is 86: 100, i.e. y 3 is longer than the claw (Fig. 4 C). Maxilliped L 5, right and left clasping organ asymmetric. Finger of right clasping organ longer and less curved than left finger. Left clasping organ with two bristles and two additional truncated setae (Fig. 4 I), right clasping organ with only 1 seta of this type (Fig. 4 J). Zenker organ with number of rings of spines varying between 25 and 27 (n= 5). Copulatory organ with hemipenis with small rounded medial shield, very wide lateral shield, a lateral appendix, postlabyrinthal spermiduct with one additional circular whorl (Fig. 4 L). Systematic position. The new species belongs to the genus Psychrodromus erected by Danielopol & McKenzie (1977), although the elongated shape of the carapace resembles carapaces of the genus Herpetocypris. However, the selvage of the LV of Herpetocypris is largely inwardly displaced, which is not the case in Psychrodromus. In some species of Psychrodromus a list exists, which runs close and in parallel to the edge on the left valve (e.g. P. betharrami (Fig. 2 in Baltan��s et al. (1993) and P. t u n i s i c u s n. sp.), but this is not the selvage. Further arguments for the species designation within the genus Psychrodromus include straight radial pore canals, both valves with small selvages, A 1 with Rome organ, natatory setae on A 2 very short, uropod weakly asymmetric, posterior setae of uropod shaped as spines, hemipenis with lateral appendix and only one additional circular whorl. Psychrodromus tunisicus n. sp. differs from the other Psychrodromus species by the size and the shape of the carapace, the claws and setae of the uropod, characteristic additional truncated setae on the clasping organs, and the male copulatory organ (see also the following determination key for the genus Psychrodromus)., Published as part of Zaibi, Chahira, Scharf, Burkhard, Viehberg, Finn Andreas, Keyser, Dietmar & Kamoun, Fekri, 2013, Preliminary report on the living non-marine Ostracoda (Crustacea) from Tunisia with the description of a new Psychrodromus species, pp. 499-516 in Zootaxa 3626 (4) on pages 503-507, DOI: 10.11646/zootaxa.3626.4.5, http://zenodo.org/record/223016

The micropaleontologic study of the oolitic dolomites From the Fkirine Formation, outcropping along the North-South Axis, allows to characterize the Upper Triassic (Norian?-Rhaetian) in Central Tunisia based on the discovery of Agathammines (Hoyenella inconstans and Agathammina austroalpina) and Aulotortus. This "Rhaetian" benthic foraminiferal assemblage, well known in the Peritethyan areas and locally associated with Gandinella falsofriedli, partially occurs in the type-locality of the Fkirine Formation ("Dorsale Tunisienne") and within the Zerzour Formation from the Saharian Shelf (Jeffara).