(based on male only). Each telson lobe with five distal spines, two lateral spines and one mesial spine. The propodi of gnathopod II rectangular shape with two L-setae on palmar corner. Ventro-posterior corner of epimeral plates I to III produced. Outer plate of maxilla I with seven long spines with 2-2-1-1-3-0-1 denticles.

The name “elburzensis” refers to Elburz Mountains in the north of Iran, where the species was found.

Holotype. Iran • male; Qazvin Province, Northeastern Qazvin City, Alamout Spring; coordinates: 36°28.56'N, 50°8.52'E. Specimens collected by S.A. Mirghaffari; 25 July 2022. Holotype with two paratypes are stored under catalogue number ZCRU Amph. 1503.

Total length of specimen 9 mm. Body strong. Head length 9% of body length. Lateral cephalic lobes sub-rounded (Fig. 3A).

Antennae I–II. Antenna I is 0.4 times body length. Peduncular articles 1–3 progressively shorter; length of peduncular article 3 exceeds half of peduncular article 2 (ratio 1.00: 1.80). Main flagellum with 20 articles (most with short setae). Accessory flagellum bi-articulated and reaching half of article 4 of main flagellum; articles with one and two setae, respectively (Fig. 3B).

Antenna II with flagellum formed of seven articles. Length ratio antenna I: II as 1: 0.49. Flagellum length is 0.9 times length of peduncle articles 4 + 5. Peduncular article 4 of antenna II is longer than article 5 (1.3: 1.00), peduncle articles 4 and 5, with three groups of simple setae each (Fig. 3C).

Mouthparts. Labium bi-lobate; both lobes with numerous fine distal and lateral setae (Fig. 4D). Mandible: right mandible with four teeth on incisor process, lacinia mobilis pluritoothed, between pars incisiva and pars molaris a row of three setae with lateral projections (Fig. 3G). Left mandible with five teeth on incisor process, lacinia mobilis with four teeth, between pars incisiva and pars molaris a row of five setae with lateral projections (Fig. 3H). Mandibular palp articles 1:2:3 represent 20%, 37% and 43% of total palp length, respectively. Proximal article without setae; second article with two setae along ventral margin and third article with one group of two A-setae, two groups of B-setae, no C-setae, eight D-setae and four E-setae (Fig. 3D). Inner plate of maxilla I with two long apical setae, outer plate with seven long spines with 2-2-1-1-3-0-1 denticles; palp bi-articulated, slightly longer than outer lobe, with two apical setae (Fig. 3 E, F). Both plates of maxilla II with numerous long distal setae (Fig. 4C) . Maxilliped with short inner plate bearing three distal spines intermixed with four distal setae and two lateral setae sub-distally; outer plate exceeding half of palp article 2, with nine spines along inner margin and three setae distally; Maxilliped palp article 3 with one group of simple setae at outer and inner margins; palp terminal article with one simple seta at outer margin, nail shorter than pedestal (Fig. 4E).

Gnathopods. Coxal plate of gnathopod I shorter than gnathopod II. Coxa of gnathopod I rectangular, broader than long, anterior and ventral margins with five setae. Basis with several single setae on anterior and posterior margins; ischium and merus with one posterior group of setae. Carpus with one group of five setae anterio-distally, bulge with setae; carpus 0.58 times basis length and 0.89 times propodus length. Propodus of gnathopod I trapezoid shape and broader than long; anterior margin with five setae in one group in addition to antero-distal group of four setae. Palm slightly convex, defined by one strong long corner S-seta accompanied laterally by three L-setae with lateral projections, on inner surface of palmar corner one short sub-corner R-seta. Dactylus reaching the posterior margin of propodus, outer and inner margins of dactylus with one and two simple setae, respectively. Nail length 0.33 times total dactylus length (Fig. 4A). Coxal plate of gnathopod II of rectangular shape, longer than broad, anterio-ventral margin with five setae. Basis with single setae on anterior and posterior margins; ischium and merus with one posterior group of setae. Carpus with one group of three setae antero-distally, bulge with long setae; carpus 0.7 times basis length and 0.90 times propodus length. Propodus of gnathopod II of rectangular shape, longer than broad; anterior margin with three setae in two groups in addition to antero-distal group of four setae. Palm slightly convex, defined by one strong long corner S-seta accompanied laterally by two L-setae with lateral projections, on inner surface of palmar corner one short sub-corner R-seta. Dactylus reaching the posterior margin of propodus, outer and inner margins of dactylus with one and two setae, respectively; nail short, 0.3 times total dactylus length (Fig. 4B).

Pereonites I–VII. Without setae.

Pereopods. Coxal plate III rectangular, length to width ratio is 1.07: 1; antero-ventral margin with four simple setae. Coxal plate IV rectangular, antero-ventral margin with five setae, posterior concavity shallow and approximately 0.1 times coxa width. Coxal plate V–VI with large anterior lobe; Coxal plate V with three setae on anterior and posterior lobes each. Coxal plate VI with two setae on anterior lobe. Coxal plate VII with one seta on posterior margin (Fig. 5A–E).

Pereopod III : IV length ratio is 1: 1.03. Dactylus III length 0.39 times propodus length, nail shorter than pedestal. Dactylus IV length 0.32 times propodus length, nail shorter than pedestal (Fig. 5A, B). Pereopods length V: VI: VII ratios as 1: 1.2: 1.36, respectively (Fig. 5C–E). Pereopod VII 0.48 times total body length. Pereopod bases V–VII with five, six and five groups of spines along anterior margins and with six, 10 and nine setae along posterior margins, respectively. Antero-ventral lobe of ischium in pereopods V–VII slightly developed. Merus and carpus in pereopods V–VII with several groups of spines and setae along anterior and posterior margins; propodus of pereopod VII longer than these in V–VI, dactyli in pereopods V–VII with one seta on outer margin, nail length of pereopod VII 0.34 times total dactylus length (Fig. 5C–E).

Pleonites I–III. Each with one seta along the dorsal margin.

Pleopods. Peduncle of pleopods I–III with two-hooked retinacles distally; Peduncle of pleopod III with two setae along of inner margin. Rami of pleopods I–III with five to eight articles (Fig. 6A–C).

Urosomites I–III. At the base of uropod I with one strong spine; Urosomites I-II postero-dorso-laterally with one and two spines, respectively. Urosomite II with two simple setae on postero-dorso-laterally. Urosomite III without setae.

Uropods. Peduncle of uropod I with six and five large spines along dorso–lateral and dorso–medial margins, respectively. Inner ramus of uropod I longer than outer ramus (ratio 1: 1.05); inner ramus with five groups of spines laterally and five spines distally; outer ramus with three groups of five spines laterally and five spines distally (Fig. 6D). Inner ramus in uropod II longer than outer, both rami with lateral and distal long spines (Fig. 6E). Uropod III normal, almost 0.2 of body length. Peduncle of uropod III with five spines on distal margin. Outer ramus bi-articulated, distal article 0.11 times proximal article. The proximal article of outer ramus bearing five and four groups of spines along inner and outer margins, respectively; distal article with setae laterally and four setae distally. Inner ramus normal, with three distal spines (Fig. 6F).

Epimeral plates I–III. With angular postero-ventral corners, plates I–III posteriorly with three, three and four setae and spines, respectively. Epimeral plates II–III each with two spines along of ventral margin (Fig. 6G).

Telson. Telson length as long as broad; each lobe with five spines distally, with two long spines and two setae laterally, with one spine mesially (Fig. 6H).

Female. Unknown.

Genus Niphargus Schiödte, 1849

(based on male only). The propodi of gnathopod II triangular shape. Gnathopod II dactylus does not reach posterior margin of palm. Pereopod VI longer than pereopod VII. Maxilliped outer plate does not reach half of the posterior margin of palp article 2. Uropod III distal article exceeds more than 80% times proximal article. Outer plate of maxilla I with seven long spines with 4-2-1-2-1-1-0 denticles.

The name “zagrosensis” refers to Zagros Mountains in the west of Iran, where the species was found.

Holotype. Iran • male; Markazi Province, 54 km to Saveh City, Kahak Spring; coordinates 35°5.28'N, 49°49.02'E. Specimens collected by S.A. Mirghaffari; 20 July 2022. Holotype with two paratypes are stored under catalogue number ZCRU Amph. 1501.

The total length of specimen 10.5 mm. Body strong and stout. Head length 10.5% of body length. Lateral cephalic lobes sub-rounded (Fig. 7A).

Antennae I–II. Antennae I 0.45 times body length. Peduncular articles 1–3 progressively shorter; length of peduncular article 3 not exceeds half of peduncular article 2 (ratio 1: 0.4). Main flagellum with 23 articles (most of which with short setae); accessory flagellum biarticulated and reaching 1/3 of article 4 of main flagellum, articles with two simple setae each (Fig. 7B). Antennae II flagellum with 11 articles, approximately 0.54 as long as antenna I. Peduncular article 4 longer than article 5, with 11 and 10 groups of simple setae, respectively. Flagellum length is 0.71 peduncle article 4 + 5 (Fig. 7C).

Mouthparts. Labium bi-lobate; with fine setae on tip of both lobes (Fig. 8D). Right mandible with four teeth on incisor process, lacinia mobilis pluritoothed; between pars incisiva and pars molaris a row of six setae with lateral projections (Fig. 7G). Left mandible with five teeth, lacinia mobilis with four teeth; between pars incisiva and pars molaris a row of six setae with lateral projections (Fig. 7H). Mandibular palp articles 1:2:3 represent 19%, 40% and 41% of total palp length, respectively. The proximal article has no setae, the second article with seven setae along ventral margin and the third article with one group of two A-setae, three groups of B-setae, no C-setae, 14 D-setae and five E-setae (Fig. 7D). Inner plate of maxilla I with two long distal simple setae; outer plate with seven long spines with 4-2-1-2-1-1-0 denticles; palp bi-articulated, slightly longer than the tip of outer lobe, with three long distal simple setae (Fig. 7E, F). Maxilla II bi-lobate (Fig. 8C). Both plates of maxilla II with numerous distal simple setae. Inner lobe with lateral simple setae (Fig. 7C). Maxilliped with short inner plate bearing four distal spines intermixed with six distal simple setae; outer plate less than half of the posterior margin of palp article 2, with 10 spines along inner margin and seven setae distally. Maxilliped palp article 3 with one proximal and one distal group of long simple setae at outer margin; palp terminal article with one seta at outer margin and two small setae at base of nail, nail shorter than pedestal (Fig. 8E).

Gnathopods. Coxa of gnathopod I shorter than gnathopod II. Coxal plate of gnathopod I trapezoid shape, ventro-posterior margins with 12 simple setae. Basis with several setae on anterior and posterior margins; ischium and merus with one posterior group of setae each. Carpus with one group of four setae antero-distally, a bulge with long simple setae; carpus 0.7 times basis length and 0.75 times propodus length. Propodus of gnathopod I rectangular shape; anterior margin with one group of five setae in addition to antero-distal group of five simple setae. Palm slightly convex, defined by one strong long corner S-seta accompanied laterally by three L-setae with lateral projections, on inner surface of palmar corner one short sub-corner R-seta. Dactylus reaching the posterior margin of propodus, outer and inner margins of dactylus with a row of two and three simple setae, respectively; nail short, 0.33 of total dactylus length (Fig. 8A).

Coxal plate of gnathopod II rectangular shape, with 13 setae along antero-ventro-posterior margins. Basis with single setae along anterior margin and with setae in group along posterior margin; ischium and merus with one posterior group of setae each. Carpus 0.4 times basis length and 0.59 times propodus length. Carpus with one group of four setae antero-distally. Propodus of gnathopod II larger than gnathopod I, triangle shape and broader than long; anterior margin with three setae in one group in addition to antero-distal group of three simple setae. Palm slightly convex, defined by one strong long corner S-seta accompanied laterally by two L-setae with lateral projections, on inner surface of palmar corner one short sub-corner R-seta. Dactylus does not reach the posterior margin of propodus, outer and inner margins of dactylus with two and three simple setae, respectively. Nail length 0.29 times total dactylus length (Fig. 8B).

Pereonites I–VII. Pereonites II and IV with one seta each; others pereonites without setae.

Pereopods. Coxal plate III rectangular shape, length to width ratio as 1.2: 1; antero-ventral margin with nine simple setae. Coxal plate IV rectangular shape, length to width ratio as 1: 1.02, antero-ventro-posterior margins with 12 simple setae, posterior concavity shallow and approximately 0.1 of coxa width. Coxal plate V with large anterior lobe, with five and three simple setae on anterior and posterior lobes, respectively. Coxal plate VI with anterior lobe, with four and three simple setae on anterior and posterior lobes, respectively. Coxal plate VII with one simple seta on posterior margin (Fig. 9A–E).

Pereopods length III: IV ratio is 1: 0.94. Dactylus III length 0.40 times propodus length, nail shorter than pedestal (Fig. 9A). Dactylus IV length 0.43 times propodus length, nail shorter than pedestal (Fig. 9B). Dactyli of pereopods III–IV with one seta on inner margin (Fig. 9A, B).

Pereopods length V: VI: VII ratios is 1: 1.28: 1.25, respectively. Pereopod VII 0.48 times total body length. Pereopod bases V–VII each with seven, seven and six groups of spines along anterior margins and 13, 13 and 14 simple setae along posterior margin, respectively. Ischium, merus and carpus in pereopods V–VII with several groups of spines and simple setae along anterior and posterior margins; propodus of pereopod VI longer than these in V and VII, dactyli of pereopods V–VII with one spine at the base of nail on inner margin, nail length of pereopod VII 0.33 times total dactylus length (Fig. 9A–E).

Epimeral plates I–III. With angular postero-ventral corner, anterior and ventral margins convex; postero-ventral corners of plates I-III with three, four and five spines and setae, respectively. Epimeral plates II–III with three and four spines along of ventral margin, respectively (Fig. 10G).

Pleonites I–III. With one simple seta along the dorsal margin each.

Pleopods I–III. Peduncle of pleopods I–III with two-hooked retinacles distally; peduncle of pleopod III with three simple setae along of inner margin. Rami of pleopods I–III with nine to 14 articles (Fig. 10A–C).

Urosomites I–III. At the base of uropod I with one strong spine. Urosomites I and II with one and three spines on postero-distally, respectively. Urosomite III without setae.

Uropods I–III. Peduncle of uropod I with seven and four large spines along dorso-lateral and dorso-medial margins, respectively. Inner ramus of uropod I longer than outer ramus (ratio 1: 1.06). Inner ramus with five groups of spines laterally and five spines distally; outer ramus with four groups of six spines laterally and five spines distally (Fig. 10D). Inner ramus in uropod II longer than outer, both rami with lateral and distal long spines (Fig. 10E). Uropod III long, almost 0.44 times body length. Peduncle of uropod III with four spines on distal margin. Outer ramus bi-articulated, distal article 87% times proximal article. The proximal article of outer ramus bearing five and four groups of spines along of outer and inner margins, respectively; distal article with several groups of simple setae laterally and four simple setae distally. Inner ramus short, with two distal spines (Fig. 10F).

Telson. Telson longer than broad; lobes slightly narrowing; each lobe with four spines apically, with two spines and two simple setae laterally (Fig. 10H).

Female. Unknown.