# A new elasmobranch fauna from the early Miocene of Sharbithat (Sultanate of Oman) reveals the teeth of an ancient fantail stingray

Sylvain Adnet, Vincent Charpentier

► To cite this version:

Sylvain Adnet, Vincent Charpentier. A new elasmobranch fauna from the early Miocene of Sharbithat (Sultanate of Oman) reveals the teeth of an ancient fantail stingray. Geologica Acta, 2022, 20 (2), pp.1-13. 10.1344/GeologicaActa2022.20.2. hal-03601210

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# A new elasmobranch fauna from the early Miocene of Sharbithat (Sultanate of Oman) reveals the teeth of an ancient fantail stingray

Sylvain Adnet¹ and Vincent Charpentier²

¹Institut des Sciences de l'Evolution de Montpellier (ISE-M)
UMR 5554 CNRS/UM/IRD/EPHE, CC064, Université de Montpellier, Montpellier, France.
E-mail: sylvain.adnet@umontpellier.fr, https://orcid.org/0000-0001-7188-1560

²Inrap, UMR 7041 CNRS, University of Nanterre
Nanterre, France. E-mail: vincent.charpentier@inrap.fr, https://orcid.org/0000-0002-8133-5931

## ABSTRACT

Here we describe a new elasmobranch assemblage consisting of isolated dental material from the Aquitanian near-shore marine deposits of the Shuwayr and Warak formations at Sharbithat, in eastern Sultanate of Oman. The faunal composition clearly indicates affinities to other early Miocene elasmobranch-bearing localities worldwide. This assemblage is predominantly composed of large and common pelagic sharks as well as teeth attributable to a new species of fantail stingray, *Taeniurops tosii*, as old as the oldest undisputable fossil records of *Taeniurops*. The study of this fossil assemblage presented here improves the knowledge of the ancient elasmobranchs that frequented the eastern Arabian coasts during the closure of the Neotethys and the birth of the Arabian Sea.

## KEYWORDS

Early Neogene. Elasmobranchs. *Taeniurops*. New species. Arabian Sea.

## INTRODUCTION

The mid-Miocene closure of the Neotethys (Terminal Tethyan Event, TTE) induced by the collision of the African-Arabian plate with the Eurasian plate is considered to be a major driver of tropical marine biodiversity (e.g. Cowman and Bellwood, 2013; Floeter et al., 2008; Harzhauser et al., 2007; Hou and Li, 2018; Liu et al., 2018; Malaquias and Reid, 2009; Renema, et al., 2008). The dynamics of the elasmobranchs that frequented the sub-basin of the Tethyan Seaway north of the Arabian Plate (Fig. 1, namely Mesopotamian Seaway [MS]) are however imperfectly understood. Although there are some records of early Miocene elasmobranch assemblages in western Neotethys (e.g. southern Europe), few are known easterly of the

*Gomphotherium* land bridge connection that permitted terrestrial interchange between Eurasia and Africa since the late early Miocene (Harzhauser et al., 2007). They include the Burdigalian elasmobranch fauna from the Moghra deposits, Egypt, (Cook et al., 2010; Priem, 1920) and from Jabal Zaltan, Libya, (Argyriou et al., 2015). With 15 sharks and rays recorded, these faunas represent the oldest eastern elasmobranch evidence in the eastern Palaeomediterranean Sea. Early Miocene elasmobranchs are unfortunately unknown from the MS deposits that have been affected by the collision between the Arabian and Eurasian plates and the simultaneous counterclockwise rotation of the Arabian plate (Bialik et al., 2019; McQuarrie and Van Hinsbergen, 2013). More intriguing, early Miocene elasmobranchs are also unknown from the Paleo-Indian Ocean coasts are also unknown if we exclude some slinking reports in rare
<figure><img src="image_2.png" /><figcaption>FIGURE 1. Location of the fossiliferous locality, SHA-34, eastern Sultanate of Oman (red star) in the present geography (left) and in the Aquitanian (22Ma) palaeogeography (right), after Bialik et al. (2019).</figcaption></figure>

articles devoted to Middle East vertebrates (e.g. Roger *et al.*, 1994; Thomas *et al.*, 1989).

A fossiliferous early Miocene locality (named thereafter SHA-34) containing fossil fishes was retrieved at the Sharbithat Bay, eastern Sultanate of Oman (Fig. 1), some 4.6km to the east-northeast of the archaeological area where prehistoric collectors lost/left a damaged fossil tooth of *Otodus (Megaselachus)* cf. *chubutensis* 5,500 years ago (Charpentier *et al.*, 2020). This ancient human collecting, and transportation testify that the fossils outcropping in SHA-34 were already spotted by Neolithic maritime hunter-gatherers, at least as for the large teeth of the great mega-toothed shark *O. (Megaselachus)* cf. *chubutensis*. Charpentier *et al.*, (2020) identified a dozen of other fish species, including very well-preserved teeth of *O. (Megaselachus) chubutensis*, among the hundred specimens they collected at SHA-34. These remains include Hemigaleidae, Carcharhinidae, Sphyrnidae and Dasytidae and species of teleosts, such as Sphyraenidae, Labridae, and large Sparidae (Charpentier *et al.*, 2020, text only). The present report aims to illustrate and discuss some of these fossil elasmobranchs and precise the systematic affiliation of the batoid species belonging to Dasyatidae reported in Charpentier *et al*. (2020).

GEOLOGICAL SETTING

Neogen fossil vertebrates are quite unique for
Sharbithat Bay, which is principally famous for its
Neolithic relics and human heritage (Maiorano et
al., 2018). If geologists reported some fossils of
invertebrates (e.g. Platel et al., 1992b) and consisting
of to date outcropping deposits in Sharbithat plain,
none belonged to vertebrates. The SHA-34 locality
(17°56′54.36″N – 56°13′36.18″E, see Charpentier
et al., 2020) is a low chalky spur belonging
stratigraphically to the Shuwayr/Warak formations. In
the Sharbithat area, including SHA-34, two stratigraphic
formations crop out: the bioclastic limestones of the
Shuwayr Formation (Fm.), and the Warak Fm. They
are two successive local units belonging to Dhofar and
Fars groups, respectively (Fournier et al., 2004; Leroy
et al., 2012; Platel et al., 1992b). Both formations,
with a thickness ranging from 150 to 250m, account
for most of the bioclastic limestones cropping out in
the coastal plain of Sharbithat and extend westwards
to Shuwaymiyah and onto the slopes of Wadi Warak.
These well-bedded coral limestones of reefal bioclastic
type are intercalated with debris flows rich in coral
fragments, echinoid spiculae and reworked foraminifera (Leroy et al., 2012, fig. 14B; Platel et al., 1992b), without any emergence and aerial exposure recorded in the Sharbithat plain (Pointu, 2007). Defined east of the Qarabiyan fault, the Shuwayr and Warack formations are cross-cut by major normal faults and considered as evidence of synsedimentary tectonics that dated the displacements along the faults to the late Oligocene or early Miocene (Fournier et al., 2004; Leroy et al., 2012; Platel et al., 1992a). The sedimentary sequence in SHA-34 is unfortunately incomplete (Fig. 2A) leading to its unprecise stratigraphic position. Platel et al. (1992b) studied the sedimentology and invertebrate fossil assemblage of both formations in the Sharbithat area and reported that the highly diversified faunas were very similar and often concentrated in the interval of debris-flow beds. These faunas mainly consist of massive corals echinoids, lamellibranchs (see also Harzhauser, 2007), and foraminifers. The presence of *Schizaster* and *Eupatagus* in beds of white limestomes with brown flint (Fig. 2B) suggests that this level belongs to the top of the Shuwayr Fm. Nevertheless, the observed abundance of *Schizaster* in bioturbed chalky white limestone (Fig. 2B) reminds that found at the base of the Warak Fm. as reported by Platel et al. (1992b).

## ELASMOBRANCH ASSEMBLAGE

The majority of the collected teeth exhibit typical abrasion by sand winds (levelling unpreferentially the enameloid crown and dentine root). In contrast, the tooth part that was embedded in the limestone is well preserved indicating minor post-mortem transportation. All specimens, grouped together as the “Sharbithat point 34” collection, are housed at the Department of Archaeology, Ministry of Heritage and Tourism of the Sultanate of Oman (reference MHT DA 52923) with the SHA-34 acronym (plus catalogue number).

### Sharks

*Otodus (Megaselachus) chubutensis* (AMEGHINO, 1901) (Fig. 3A, B): A dozen teeth collected from the bioclastic chalky limestone at the SHA-34 locality (Fig. 2B). Some teeth from this locality are figured in Charpentier *et al.* (2020), and two are figured here (Fig. 3A-B). Considered as the ancestor (Perez *et al.*, 2019), of the famous mega-toothed shark *Otodus (Megaselachus) megalodon* AGASSIZ, 1843, *Otodus (Megaselachus) chubutensis* represents the largest toothed shark of early Miocene age that predate preferentially past marine mammals. Some indetermined pieces of ribs and of other bones recovered in SHA-34

<figure><img src="image_3.png" /><figcaption>**FIGURE 2.** A) Sedimentologic log of Sharbithat plain modified after Platel *et al.* (1992b). 1: White chalky limestone with brown flint and echinoids; 2: Massive bedded yellow marly limestone with small blocks, oysters, other molluscs, corals, echinoids and foraminifera; 3: Alternating thin-bedded green to yellow marly siltstone and white biocalcarenite; 4: Yellow to white bioclastic limestone with molluscs and large foraminifera; 5: Ancient beach-rock. Abbreviation (U for Unconformity). B) SHA-34 locality and, at left from top to bottom: *Otodus (Megaselachus) chubutensis*, and the *echinoids Schizaster* and *Eupatagus*).</figcaption></figure>
could indicate the occurrence of large marine mammals in the area and thus, possible ecological interaction between sharks and marine mammals. Contrary to the majority of large oceanic sharks that mainly hunt large bony fish, post Eocene species of *Otodus* (*Carcharocles*) and *Otodus* (*Megaselachus*) probably preferred food marine mammals which made a nutritious, high-calorie, scrumptious snack for its predators. As marine mammals doubled in size over the course of the late Paleogene and Neogene, *Otodus* (*Carcharocles*) and *O. (Megaselachus)*, started to grow rapidly. However, *Pimiento and Balk* (2015) concluded that the body size of its youngest and famous representative, *O. (Megaselachus) megalodon*, seems to have been surprisingly stable during the Neogene. In fact, the increase in body size is relatively regular along chronospecies of *Otodus*, between *Otodus* (*Otodus*) *obliquus* (8m Total Length (TL)) and the giant *O. (Megaselachus) megalodon* (15m TL) (*Shimada et al.*, 2020). Maximum length of the body of *O. (Megaselachus) chubutensis* from Oman was deduced from linear regression following *Shimada et al.* (2020): $TL(m)= 11.784cCH - 0.331$ with $cCH$ (mm) being the crown height of first/second anterior tooth. Total length of the largest Sharbithat specimen (*Charpentier et al.*, 2020, fig. 5B) is close to 6m, indicating that local representatives of this large predator were probably young individuals compared to contemporaneous adults that reached 10 meters long.

*Isurus* cf. *oxyrinchus* RAFINESQUE, 1810 (Fig. 3C, D): Two small (<1cm) teeth probably belonging to juvenile individuals. Unornamented crown, lack of numerous denticles and a massive root without trace of nutritive groove, relative minute size (less than 1cm), and presence of a pair of very tiny denticles in the upper tooth (Fig. 3D) are characteristics present in lamnid juvenile teeth. Crown and root morphologies are quite like those of figured Miocene representatives of *Isurus oxyrinchus* (e.g. *Reneicke et al.*, 2011: pl. 35-41), while the presence of tiny denticles remains intriguing compared to juvenile living specimens (*Bemis et al.*, 2015).

*Galeocerdo aduncus* AGASSIZ, 1843 (Fig. 3E–G): Compared to the coeval *Galeocerdo mayumbensis*, known in the Atlantic, the eastern Mediterranean (*Argyriou et al.*, 2015) and the south Indian Ocean (*Andrianavalona et al.*, 2015) during the early-middle Miocene period; the teeth of *G. aduncus* are smaller, have a more gracile crown with mesial cutting edge without any compound serration. These last features allow to distinguish the teeth of *G. aduncus* from those of the extant species *Galeocerdo cuvier* known from the mid Miocene. the morphology of *G. aduncus* teeth is closer to the morphology of the teeth of the small Paleogene *Galeocerdo latidens*. *Galeocerdo aduncus* is not an uncommon fossil tiger shark in early-middle Miocene deposits. It has been recorded in many

localities, particularly in the Eastern Pacific, North Atlantic, Paratethys, and Mediterranean realms (e.g. Barthelt *et al.*, 1991; Bracher and Unger, 2007; Carrillo-Briceño *et al.*, 2020; Cappetta, 1970; Marsili *et al.*, 2007; Müller, 1999; Purdy, 1998; Purdy *et al.*, 2001; Probst, 1878; Reinecke *et al.*, 2011; Ward and Bonavia, 2001). The living tiger shark (*G. cuvier*) is a widespread shark that frequents all oceanic realms. Its Miocene fossil representatives (*G. aduncus* and *G. mayumbensis*) seem to have had the same ecological capability being collected in many coastal deposits around the world (Carrillo-Briceño *et al.*, 2019; Cappetta, 2012).

*Hemipristis serra* AGASSIZ, 1835 (Fig. 3H–J): The extinct snaggletooth shark species is very-well represented in worldwide Miocene deposits and its teeth became larger, though less numerous, in the Pliocene and until early Pleistocene in Gulf of Mexico (Ebersole *et al.*, 2017 and references herein). Distinction with its close and unique modern relative species *H. elongata* (KLUNZINGER, 1871) from the tropical shallow waters of the Indo-Pacific area is tenuous excepted its larger size (see Chandler *et al.*, 2006) and root histology (Jambura *et al.*, 2018).

*Carcharhinus priscus* (AGASSIZ, 1843) (Fig. 3K–P): As expected for this common fossil species, the upper teeth (Fig. 3K–M2) have a crown with a fine to triangular cusp with fully serrated cutting edges, serration being coarser on lateral heels than on median cusp where they decrease toward the top of the cusp. The crowns in the anterior teeth are more straight and larger (Fig. 3K) than those on the posterior teeth (Fig. 3M1, 2). The lower teeth (Fig. 3N-P2) have an unserrated crown, with a cusp more medially erected and distinct from mesial heel compared to upper teeth. The genus *Carcharhinus* includes 34 living species of “Requiem” sharks (e.g. Pollerspöck and Straube 2021) with many fossil representatives in Miocene deposits. Differences on tooth morphology between many living species of *Carcharhinus* are very tenuous (Naylor and Marcus, 1994; Soda *et al.*, 2017) and their use in taxonomy is complicated always having a blend of isolated teeth from several *Carcharhinus* species in Neogene deposits. However, few species occur in latest Paleogene – earliest Miocene. In addition to the most common and worldwide *C. priscus* (Cappetta, 2012), two other coeval species: *C. ackermanii* SANTOS AND TRAVASSOS, 1960 and *C. gibbesii* (WOODWARD, 1889) inhabited the Atlantic Ocean. However, both easily differ from *C. priscus* in having cusp of their upper teeth frequently unserrated (e.g. Aguilera *et al.*, 2017, fig. 3). With a global tooth morphology closer to the living copper and blacktip sharks (Reinecke *et al.*, 2011), *C. priscus* is usually reported in many early Miocene deposits from tropical to temperate latitudes.

*Sphyrna laevissima* (COPE, 1867) (Fig. 3Q1,2): Often incorrectly synonymised with the living species of the
<figure><img src="image_4.png" /></figure>

**FIGURE 3.** Sharks from SHA-34. A-B) *Otodus (Megaselachus) chubutensis*, A (SHA-34-4) antero-lateral tooth, lingual view, B (SHA-34-5) antero-lateral tooth, lingual view. C-D) *Isurus cf. oxyrinchus*, C (SHA-34-6) anterior upper tooth, C1 lingual and C2 labial views. D (SHA-34-7) lateral lower tooth, labial view. E-G) *Galeocerdo aduncus*, E (SHA-34-8), F (SHA-34-9), antero-lateral teeth, labial view, G (SHA-34-10) posterior tooth, labial view. H-J) *Hemipristis serra*, H (SHA-34-11) upper tooth; H1 labial and H2 lingual views; I (SHA-34-12) anterior lower tooth, labial view; J (SHA-34-13) lateral lower tooth in profile. K-P) *Carcharhinus priscus*, K (SHA-34-14) first anterior upper tooth, labial view; L (SHA-34-15) anterior upper tooth, labial view; M (SHA-34-16) lateral upper tooth, M1 labial and M2 lingual views; N (SHA-34-17) lower anterior tooth, labial view; O (SHA-34-18), P (SHA-34-19) lower lateral teeth, O1, P1 labial and O2, P2 lingual views. Q, *Sphyrna laevissima* (SHA-34-20), Q1 labial and Q2 lingual views.
hammer shark *Sphyrna zygaena* (LINNAEUS, 1758) (see Reinecke *et al.*, 2011 for a discussion). Teeth attributable to *S. laevissima* are frequently collected in late Oligocene to middle-?late Miocene coastal deposits of the Western and Eastern Atlantic Ocean and Eastern Pacific Ocean (see Carrillo-Briceño *et al.*, 2019; Kent, 2018).

## Batoids

No macrofossil corresponding to usual large myliobatid teeth/spines nor pristid rostral denticles or vertebrae (sawfish) were collected in SHA-34. The unique fossil evidence of a batoid in SHA-34 are two dozen oral small teeth belonging to a unique Dasyatinae stingray (Charpentier *et al.*, 2020). These minute teeth look like those of the Miocene *Dasyatis cavernosa* (Probst, 1877), reassigned to the dasyatid genus *Taeniurops* by Bor *et al.* (2012).

Dasyatidae JORDAN AND GILBERT, 1879

subfamily Dasyatinae

*Taeniurops* GARMAN, 1913

**Type species.** *T. grabatus* (GEOFFROY SAINT HILAIRE, 1817) – living species

*Taeniurops tosii* nov. sp. (Fig. 4A-M)

**Type material.** Holotype (SHA-34-28) (Fig. 4H) is a lateral tooth of a possible male, whose cusp being few, erected and developed.

**Type Locality and Age.** SHA-34 (17°56′54.36″ N - 56°13′36.18″ E), Sharbithat area – Dhofar, Sultanate of Oman - top of Shuwayr Fm. (Dhofar Group) / base of Warak Fm. (Fars Group), Aquitanian in age.

**Derivation nominis.** Species name dedicated to Maurizio Tosi (1944-2017), full Professor at the University of Bologna (Italy), archaeologist and pioneer of maritime archaeology of ancient societies in the Indian Ocean. His main field of study was the formative processes of complex human societies.

**Diagnosis.** Teeth of medium size (up to 5mm width); crown cuspidated in anterior teeth of male and ovoid in female and lateral teeth of male. The crown has a distinctly hollowed labial face forming an oral depression bordered by a sinuous crest labially and by a regular transverse crest lingually. Enameloid of crown mainly smooth, except around labial crest. Lingual face trapezoid shaped, whereas its lingual visor being straight to undulating with median concavity. Root is quite wide and lingually extended in anterior rows with two lobes principally rounded and separated by a large nutritive groove in all tooth rows.

**Description.** In both male and female, tooth crown with a distinctly hollowed labial face forming an oral depression bordered by ornamented crests labially and by

a smooth transverse crest lingually. Labial visor free of enameloid ornamentation and rounded in profile. Labial crest weakly developed in cuspidated teeth (Fig. 4A–D) to more salient in lateral male teeth and female teeth (Fig. 4I). Irregular ridges of enameloid developed preferentially around labial crest of these lateral teeth (Fig. 4I2). In male with cuspidated teeth (Fig. 4A–D), the transverse crest weakly arching in profile (Fig. 4A2, D1), the cusp being quite strait. This cusp being triangular (anterior teeth) to very short and obtuse (lateral teeth) in oral view. Transverse crest sharp and rectilinear in females or non-mating males. Transverse crest devoid of any ornamentation of enameloid on all teeth. Lingual face entirely smooth and trapezoid shaped. Lingual visor straight (Fig. 4B, C, E) to undulating (Fig. 4G, H, L, M) in lingual view. When undulating, a median concavity is observed just over nutritive groove of root (e.g. Holotype, Fig. 4H). The root being as wider as crown and lingually extended in anterior tooth files (Fig. 4A–D) with two lobes, principally rounded and separated by a large nutritive groove in all tooth files. In basal view, one or two small nutrient foramens opening in groove. Labially, numerous small foramens visible under crown-root boundary (e.g. Fig. 4B2, D2, E2).

**Discussion.** Most of the subfamily Dasyatinae sensu Last *et al.* (2016) have jaws presenting sexual heterodonty with male teeth displaying a long, tapered cusp in all or some tooth files. Sexual dimorphism in *T. tosii* nov sp. seems light, as observed in the extant species of *Taeniurops* (Cappetta and Cavallo, 2006; Herman *et al.*, 1999). Morphologically, teeth of *Taeniurops* can be separated from those of other Dasyatinae (e.g. *Dasyatis*) by a crown having a distinctly hollowed labial face, the resulting depression being usually bordered by sharp crests labially and lingually (Cappetta, 2012). Moreover, the root lobes seem well-expended lingually and separated by a wider nutritive groove than in other Dasyatinae (*Dasyatis* genus included). Compared to the single fossil species of *Taeniurops*, *T. cavernosus* (Probst, 1877), the weakly arched transverse crest in profile and undulating lingual visor (with a median concavity) observed in the new species are different from the typical teeth of *T. cavernosus* (e.g. Bor *et al.*, 2012, plate 49). It instead resembles the Pliocene specimens *Taeniurops* aff. *grabatus* figured by Cappetta and Cavallo (2006). However, the new species easily separates from all described species by having an enameloid essentially smooth. Herman *et al.* (1999) and Cappetta (2012) figured teeth of the round fantail stingrays *Taeniurops grabatus* (Dasyatinae) but tooth illustration of the second living species *Taeniurops meyeni* (MÜLLER AND HENLE, 1841) was still unknown. Nevertheless, Cappetta and Cavallo (2006) reported that males of *T. meyeni* do not seem to have cuspidated teeth, in agreement with our own observations of some fresh specimens of *T. meyeni* (Fig. 4T–U) from the Indo-Pacific. Indeed, dental
<figure><img src="image_5.png" /><figcaption>**FIGURE 4.** A1-M) *Taniurops tosii* nov. sp. A1-H2) male teeth from anterior (A) to lateral (H) files; I1-M. "female" teeth (or non-matting male teeth). A (SHA-34-21), A1 occlusal and A2 lateral views; B (SHA-34-22), B1 lingual and B2 labial views; C (SHA-34-23), C1 occlusal and C2 lingual views; D (SHA-34-24), D1 lateral and D2 labio-basal views; E (SHA-34-25), E1 lingual and E2 labial views; F (SHA-34-26), F1 labial and F2 basal views; G (SHA-34-27), G1 lingual and G2 occlusal views; H (SHA-34-28, Holotype), H1 lingual and H2 occlusal views; I (SHA-34-29), I1 lingual and I2 occlusal views; J (SHA-34-30), J1 lingual and J2 basal views; K (SHA-34-31), K1 labial and K2 basal views; L (SHA-34-32), lingual view; M (SHA-34-33), lingual view. N-T) *Taeniurops meyeni* (Collection from the Montpellier University, France: UM REC 1138M, Female, DW= 155cm) from Indian Ocean, N (Anterior lower tooth), N1 lingual and N2 basal views; O (anterior lower tooth), O1 lingual and O2 profile views; P (anterolateral lower tooth), P1 lingual and P2 labial views; Q (lateral tooth), Q1 lingual and Q2 labial views; R (lateral tooth), R1 lingual and R2 profile views; S (lateral tooth), S1 lingual and S2 occlusal views; T (jaws) symphyseal region of upper and lower jaws. U) *T. meyeni* (Collection from the Montpellier University, UM REC0815M, young Male, DW= 100cm) from Indonesia, lower jaw.</figcaption></figure>
sexual dimorphism appears to be modestly pronounced in *T. meyeni* teeth, unless this reflected that all collected specimens were fished during the non-breeding period (Kajiura and Tricas, 1996). Surprisingly, teeth of *T. meyeni* do not resemble those of its sister species *T. grabatus*. Tooth morphology of *T. meyeni* is quite reminiscent of that of *Dasyatis* with e.g. lingual face of crown without strongly undulating visor (although undulating as in Fig. 4Q1). However, the root is well extended lingually (Fig. 4O2, R2), the nutritive groove opens widely in lingual view (Fig. 4T-S), and if enameloid of crown is lesser ornamented than in *T. grabatus*, it remains more than in *T. tosii* nov. sp.

The fossil teeth of *Taeniura* and *Taeniurops* have mostly been confused with those of the genus *Dasyatis*. Cappetta (2012) synthetized the dental difference between *Taeniura* and *Taeniurops*, considered as subgenus of *Taeniura* since Garman (1913) and until its resurrection by Last and Stevens (2009) for two valid living species, the Atlantic and Mediterranean *Taeniurops grabatus* and the Indo-Pacific *Taeniurops meyeni* (Last et al., 2016; Naylor et al., 2012). Cappetta (2012) also succinctly updated the fossil record of *Taeniurops* that now includes the Zanclean Mediterranean representatives of *T. grabatus* (Cappetta and Carvalho, 2006) and *T. cavernosus* from the Burdigalian of Bavaria, Germany. The latter (initially attributed to *Dasyatis* or *Taeniura*) is a common dasyatid taxa recovered in early-middle Miocene deposits from seas covering principally western and southern Europe (Bor et al., 2012; Bracher and Unger, 2007; Cappetta, 1970; Probst, 1877; Reinecke et al., 2008, 2011; Vialle et al., 2011). The Aquitanian species *T. tosii* nov. sp. (this work) and the early Burdigalian *T. cavernosus* (Reinecke et al., 2008) represent the oldest occurrence of the genus *Taeniurops*. Teeth of this coastal dasyatid genus are more frequently collected since middle-late Burdigalian, from Venezuela (Carrillo-Briceño, et al., 2016) to south France and Germany (Bor et al., 2012; Cappetta, 1970; Probst, 1877; Reinecke et al., 2008, 2011). Principally affiliated to the extant species *T. grabatus*, the Late Miocene-Pliocene records seem to reflect the current distribution of living species because its fossils are known from Panama (Pimiento et al., 2013), Portugal (Antunes et al., 1999) to Italia (Cappetta and Cavallo 2006).

DISCUSSION

Concerning the paleoenvironmental inference, Platel
et al. (1992b) suggested that the Warak Fm was deposited
in the proximity of a N-S paleocanyon developed in a
context of active local subsidence. Unfortunately, this small
taxic association is irrelevant to conduct or support any
paleoenvironmental consideration, as the main taxa are
predominantly pelagic, with the possible exception of the
new stingray.

Concerning the elasmobranch fossil record and dating interest, some previous paleontological studies reported fossil remains of sharks and rays in the Sultanate of Oman. Koot et al. (2013) described teeth, dermic denticules and fin spines of Ctenacantiforms and Hybodontiforms from the Middle Permian–Lower Triassic in the Haushi-Hugf region. Adnet et al. (2007) and Thomas et al. (1989) mentioned teeth of early Oligocene sharks and rays from Taqah and Thaytiniti, in the Dhofar region, and Roger et al. (1994) a rare spine remain of a ray from Ghaba in the early Miocene of the Dam Fm., in the region of Hugf. More broadly, Miocene elasmobranchs from the Arabian Plate are scarce and rarely illustrated. The only reported occurrences are *Galeocerdo* cf. *aduncus*, *Hemipristis serra*, *Carcharinus* aff. *priscus*, *C*. aff. *plumbeus*, *Scoliodon* sp., *Negaprion* aff. *eurybathrodon*, *Sphyrna* sp. *Dasyatis* sp. *Myliobatis* sp. *Aetobatis arcuatus*, and *Rhinoptera* sp. in the late lower Miocene of the Dam Fm., As-Sarrar, Saudi Arabia (Cappetta in Thomas et al., 1982, unfigured), and *Dasyatis sensu lato* and *Pristis* sp. in the UAE (Otero, in press), and those previously detailed from Ghaba in the Sultanate of Oman.

All the fossil taxa from SHA-34 are consistent with an Aquitanian age, from earliest Aquitanian (top of the Shuwayr Formation) to latest Aquitanian (base of the Warack Formation). The Aquitanian large teeth of *O. (Megaselachus) chubutensis*, show all diagnostic features, such as crowns exhibiting triangular principal cusps with well-serrated cutting edges and separate lateral cusplets, at least in the smallest teeth, whereas the mesial ones seem to disappear completely in the largest specimen, prefiguring the evolutionary trend observed during the early-middle Miocene period and toward the youngest species *O. (Megaselachus) megalodon* in USA (Perez et al., 2019). While this association of widely distributed sharks (e.g. *O. (Megaselachus) chubutensis*, *G. aduncus*, *H. serra*, *C. priscus*, *S. laevissima*) is relatively common in early Miocene (Middle East area included, see above), co-occurrence with the new species *T. tosii* nov. sp. is currently unique in tropical fossil elasmobranch faunas. Early Miocene elasmobranch faunas from the tropical belt westerly (e.g. Eastern Pacific, Atlantic, Central Paratethys and Mediterranean realms) are quite well-known (e.g. Argyriou et al., 2015; Cappetta, 1970; Carrilo-Briceno et al., 2016, 2019; Case, 1980; Cook et al., 2010; Kent, 2018; Marsili et al., 2007; Pimiento et al., 2013; Purdy et al., 1998; Suarez et al., 2006). They display similar taxic associations of large pelagic sharks with *O. (Megaselachus) chubutensis*, *Isurus* spp. *Galeocerdo* spp., *Hemipristis serra*, *Carcharinus* spp. as observed at Sharbithat, eastern Sultanate of Oman. Elasmobranchs from early Miocene deposits from the tropical belt easterly (e.g. Indian Ocean, Indo-Malaysian region and western Pacific) are lesser known. Numerous Indian palaeontologists of
the last century (e.g. *Mehrotra et al.*, 1973; Sahni and *Mehrotra*, 1981; Tewari, 1959) and more recently Patnaik *et al.* (2014) reported common faunal association from the early Miocene of Kutch, India (e.g. *O. (Megaselachus) chubutensis*, *Galeocerdo* spp., *Hemipristis serra*, and *Carcharhinus* sp.) but no fossil could be currently compared with the new *Taeniurops* species. Welcomme *et al.* (1997) also reported a Burdigalian fauna from Baluchistan, Pakistan (e.g. *Carcharhinus*, *Galeocerdo*, *Hemipristis*, *Sphyrna*) with the presence of a stingray, *Dasyatis* sp., but the latter material is too fragmentary to compare with our material. Southerly, Priem (1907) and Andrianavalona *et al.* (2015) also reported elasmobranch associations from the Miocene of the Mahajanga Basin, northwestern Madagascar, with quite similar association of sharks with *O. (Megaselachus)*, *Carcharhinus*, *Galeocerdo*, *Sphyrna*, *Hemipristis* and stingrays. Presence of *C. priscus* and *G. mayumbensis* would suggest an early to middle Miocene age according to the last authors. However, occurrence of *O. (Megaselachus) megalodon* in the Miocene of Mahajanga Basin suggests that the fauna at SHA-34 is somewhat oldest than those from northwestern Madagascar. Knowledge of early Miocene elasmobranchs from Indo-Malaysian region are mainly based on old literature (e.g. de Beaufort, 1926; Martin, 1883-1887; Noetling, 1901) and unprecise dating. One can suspect that some taxa reported by Leriche (1954) as *O. (Megaselachus) megalodon* var. indica from Java, Indonesia, are conspecific with *O. (Megaselachus) chubutensis* but most of these reports require revisions as recently performed by Marramà *et al.* (2018) on a holomorphic stingray from the early Miocene of Sulawesi, Indonesia. The tooth morphology of the revised *Protohimantura Marrama* *et al.* (2018) is consistent with that of *Himantura* and by this, clearly different from *Taeniurops tosii* nov. sp.

## CONCLUSION

Bialik *et al.* (2019) and Torfstein and Steinberg (2020) have recently updated the timing (late Oligocene–middle Miocene) and tempo of closure of the MS that resulted from the northward movement of the African–Arabian plates. Bialik *et al.* (2019) pointed out that water mass exchange between the Mediterranean Sea and Indian Ocean via the MS was strongly reduced at ca. 19.7Ma, at least 6Ma before the terminal closure of the seaway (at 13.8Ma) that coincides with *Gomphotherium* land bridge event. A second marine connection between both oceanic realms across the Red Sea may still have existed (Segev *et al.*, 2017), until at least the Aquitanian (Fig. 1). However, the feasibility and evolution of significant exchange of water masses between the Mediterranean Sea and Indo-Pacific oceans by the putative Red Sea Gateway is still debated (Bialik *et al.*, 2019; Torfstein and Steinberg, 2020). The

elasmobranch fauna from the Sultanate of Oman may illustrate what the fauna living in the new north-western extremity of the Indian Ocean (prefiguring the Arabian sea fauna) looked like. This fauna includes most of the pelagic sharks that dwelled in the early Miocene tropical seas plus a new fantail stingray *Taneiurops tosii* nov. sp. The latter species, as old as the coeval fantail stingray species *T. cavernosus* known as far as western Mediterranean, could indicate that splitting of the two *Taneiurops* lineages was before the beginning of the Neotethys closure. This clearly supports the assumption of a reduced water mass exchange between Indian Ocean and Mediterranean Sea even earlier than earliest Miocene. If both living species of fantail stingrays could result from such dispersal and vicariance processes, it would support the hypothesis that Neotethys closure played a main role in establishment of modern tropical marine biodiversity.

## ACKNOWLEDGMENTS

We gratefully thank Jorge Carrillo-Briceño and Gloria Arratia for their constructive criticism and comments on the manuscript. We also wish to thank the Ministry of Heritage and Tourism of the Sultanate of Oman for granting us permission to carry out fieldwork along the Omani Arabian sea shores, with specific reference to H.E. Salim Mohammed Al Mahruqi, Minister; Mr. Sultan Said Al-Bakri, Director General for Archaeology; Mr Khamis Al Asmi, Director of the Department of Excavations and Archaeological Studies; M. Ali Al Mashani of the Salalah department. We would like to thank the Consultative Commission for Excavations Abroad of the French Ministry of European and Foreign Affairs, the Agence Nationale de la Recherche with the *NeoArabia* Program (ANR-16-CE03-0007, CNRS, Inrap, MNHN) for funding the archaeological Mission «Archaeology of the Arabian Sheashores».

## REFERENCES

Adnet, S., Antoine, P-O., Hassan Baqri, S.R., Crochet, J.-Y., Marivaux, L., Welcomme, J.-L., Metais, G., 2007. New tropical carcharhinids (chondrichthyes, carcharhiniformes) from the late Eocene–early Oligocene of Balochistan, Pakistan: Paleoenvironmental and paleogeographic implications. Journal of Asian Earth Sciences, 30, 303-323. DOI: https://doi.org/10.1016/j.jseaes.2006.10.002

Agassiz, L., 1835-1843. Recherches sur les Poissons fossiles. Petitpierre et Prince (text) and H. Nicolet (plates). Switzerland, Neuchâtel, 188pp.

Aguilera, O., Luz, Z., Carrillo-Briceño, J.D., Kocsis, L., Vennemann, T.W., de Toledo, P.M., Nogueira, A., Amorim, K.B., Moraes-Santos, H., Polck, M.R., Ruivo, M.L., Linhares, A.P., Monteiro-Neto, C., 2017. Neogene sharks and rays from the Brazilian ‘Blue Amazon’. PLOS ONE,
12(8), e0182740. DOI: https://doi.org/10.1371/journal.pone.0182740

Ameghino, F., 1901. L'âge des formations sédimentaires de Patagonie. Anales de la Sociedad Científica Argentina, 51, 20-39, 65-91.

Andrianavalona, T.H., Ramihangihajason, T.N., Rasoamiaramanana, A., Ward, D.J., Ali, J.R., Samonds, K.E., 2015. Miocene Shark and Batoid Fauna from Nosy Makamby (Mahajanga Basin, Northwestern Madagascar). PLOS ONE, 10, e0129444. DOI: https://doi.org/10.1371/journal.pone.0129444

Antunes, M.T., Balbino, A.C., Cappetta, H., 1999. Sélaciens du Miocène terminal du bassin d'Alvalade (Portugal). Essai de synthèse. Ciências da Terra, 13, 115-129.

Argyriou, T., Cook, T.D, Muftah, A.M., Pavlakis, P., Boaz, N.T., Murray, A.M., 2015. A fish assemblage from an early Miocene horizon from Jabal Zaltan, Libya. Journal of African Earth Sciences, 102, 86-101. DOI: https://doi.org/10.1016/j.jafrearsci.2014.11.008

Barthelt, D., Fejfar, O., Pfeil, F.H., Unger, E., 1991. Notizen zu einem Profil der Selachier-Fundstelle Walbertsweiler im Bereich der miozänen Oberen Meeresmolasse Süddeutschlands. Münchner Geowissenschaftliche Abhandlungen Reihe A: Geologie und Paläontologie, 19, 195-208.

de Beaufort, L.F., 1926. On a collection of marine fishes from the Miocene of South Celebes. Jaarboek van het Mijnwezen in Nederlandsch Oost Indies Weltefreden Java 1925, 117-148.

Bemis, W.E., Moyer, J.K., Riccio, M.L., 2015. Homology of lateral cusplets in the teeth of lamnid sharks (Lamniformes: Lamnidae). Copeia, 103, 961-972. DOI: http://dx.doi.org/10.1643/CG-14-109

Bialik, O.M., Franck, M., Betzler, C., Zammit, R., Waldmann, N.D., 2019. Two-step closure of the Miocene Indian Ocean Gateway to the Mediterranean. Scientific Reports, 9, 8842. DOI: https://doi.org/10.138/s41598-019-45308-7

Bor, T.J., Reinecke, T., Verschueren, S., 2012. Miocene Chondrichthyes from Winterswijk - Miste, the Netherlands. Palaeontos, 21, 1-136.

Bracher, H., Unger, E., 2007. Untermiozän Haie und Rochen. Altheim, 183pp.

Cappetta, H., 1970. Les sélaciens du Miocène de la région de Montpellier. Palaeovertebrata Mémoire Extraordinaire, 1-139.

Cappetta, H., 1973. Les Sélaciens du Burdigalien de Lespignan (Herault). Geobios, 6, 211-223.

Cappetta, H., Cavallo, O., 2006. Les selaciens du Pliocene de la région d'Alba (Piémont, Italie Nord-ouest). Estratto da “Rivista Piemontese di Storia Naturale”, XXVII, 33-76.

Cappetta, H., 2012. Vol. 3E: Chondrichthyes Mesozoic and Cenozoic Elasmobranchii: Teeth. In: Schultze, H.-P (ed.). Handbook of Paleozoichthyology. Munich, Verlag Dr. Friedrich Pfeil, 512pp.

Carrillo-Briceño, J., Aguilera, O., De Gracia, C., Aguirre-Fernández, G., Kindlimann, R., Sánchez-Villagra, M., 2016. An Early Neogene Elasmobranch fauna from the southern Caribbean (Western Venezuela). Palaeontologia Electronica, 19.2.27A, 1-32. DOI: https://doi.org/10.26879/664

Carrillo-Briceño, J.D., Luz, Z., Hendy, A., Kocsis, L., Aguilera, O., Vennemann, T., 2019. Neogene Caribbean elasmobranchs: diversity, paleoecology and paleoenvironmental significance of the Cocinetas Basin assemblage (Guajira Peninsula, Colombia). Biogeosciences, 16, 33-56. DOI: https://doi.org/10.5194 bg-16-33-2019

Carrillo-Briceño, J.D., Villafaña, J.A., De Gracia, C., Flores-Alcívar, F.F., Kindlimann, R., Abella, J., 2020. Diversity and paleoenvironmental implications of an elasmobranch assemblage from the Oligocene-Miocene boundary of Ecuador. PeerJ, 8, e9051. DOI: https://doi.org/10.7717/peerj.9051

Case, G.R., 1980. A Selachian Fauna from the Trent Formation; Lower Miocene (Aquitanian) of Eastern North Carolina. Palaeontographica Abteilung A, 171, 75-103.

Chandler, R.E., Chiswell, K.E., Faulkner, G.D., 2006. Quantifying a possible Miocene phyletic change in Hemipristis (Chondrichthyes) teeth. Palaeontologia Electronica, 9, 1-14.

Charpentier, V., Adnet, S., Cappetta, H., 2020. The tooth of a giant sea creature *Otodus (Megaselachus)* in the material culture of Neolithic maritime hunter-gatherers at Sharbithat (Sultanate of Oman). International Journal of Osteoarchaeology, 30(6), 835-842. DOI: https://doi.org/10.1002/oa.2914

Cook, T.D, Murray, A.M., Simons, E.L., Attia, Y.S., Chatrath, P., 2010. A Miocene selachian fauna from Moghra, Egypt. Historical Biology, 22, 78-87. DOI: https://doi.org/10.1080/08912960903249329

Cope, E.D., 1867. An addition to the vertebrate fauna of the Miocene period, with a synopsis of the extinct Cetacea of the United States. Proceedings of the Academy of Natural Sciences of Philadelphia, 19, 138-156.

Cowman, P.F., Bellwood, D.R., 2013. The historical biogeography of coral reef fishes: global patterns of origination and dispersal. Journal of Biogeography, 40, 209-224.

Ebersole, J.A., Ebersole, S.M., Cicimurri, D.J., 2017. The occurrence of early Pleistocene marine fish remains from the Gulf Coast of Mobile County, Alabama, USA. Palaeodiversity, 10, 97-115. DOI: https://doi.org/10.18476/pale.v10.a6

Floeter, S.R., Rocha, L.A., Robertson, D.R., Joyeux, J.C., Smith-Vaniz, W.F, Wirtz, P, Edwards, A.J., Barreiros, J.P, Ferreira, C.E.L., Gasparini, J.L., Brito, A., Falcón, J.M., Bowen, B.W, Bernardi, G., 2008. Atlantic reef fish biogeography and evolution. Journal of Biogeography, 35, 22-47.

Fournier, M., Bellahsen, N., Fabbri, O., Gunnell, Y., 2004. Oblique rifting and segmentation of the NE Gulf of Aden passive margin. Geochemistry Geophysics Geosystems, 5(11), 24.

Garman, S., 1913. The Plagiostomia (sharks, skates and rays). Memoirs of the Museum of Comparative Zoology, Harvard, 36, 1-528. DOI: https://doi.org/10.5962/bhl title.43732

Geoffroy St Hilaire, E., 1817. Poissons du Nil, de la Mer Rouge et de la Méditerranée. In: Description de l'Egypte ou recueil des observations et des recherches qui ont été faites en Égypte pendant l'expédition de l'Armée française. Publié par les ordres de sa Majesté-L'Empereur Napoléon le Grand, 18-27.
Harzhauser, M., 2007. Oligocene and Aquitanian gastropod faunas from the Sultanate of Oman and their biogeographic implications for the early western Indo-Pacific. Palaeontographica Abteilung A, 280, 75-121.

Harzhauser, M., Kroh, A., Mandic, O., Piller, W.E., Gohlich, U., Reuter, M., Berning, B., 2007. Biogeographic responses to geodynamics: a key study all around the Oligo-Miocene Tethyan Seaway. Zoologischer Anzeiger, 246, 241-256.

Herman, J., Hovestadt-Euler, M., Hovestadt, D.C., Stehmann, M., 1999. Contributions to the study of the comparative morphology of teeth and other relevant ichthyodorulites in living supraspecific taxa of chondrichthyan fishes. Part B: Batomorphii. N°4b. Order Rajiformes -Suborder Myliobatoidei -Superfamily Dasyatoidea -Family Dasyatidae -Subfamily Dasyatinae -Genera: Taeniura, Urogymnus, Urolophoides -Subfamily Potamotrygoninae -Genera: Disceus, Paratrygon, Plesiotrygon and Potamotrygon (incl. supraspecific taxa of uncertain status and validity). Family Urolophidae -Genera: Trygonoptera, Urolophus and Urotrygon - Superfamily Myliobatoidea -Family Gymnuridae -Genus Aetoplatea. Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, 69, 161-200.

Jambura, P.L., Pfaff, C., Underwood, C.J., Ward, D.J., Kriwet, J., 2018. Tooth mineralization and histology patterns in extinct and extant snaggletooth sharks, *Hemipristis* (Carcharhiniformes, Hemigaleidae) - Evolutionary significance or ecological adaptation? PLOS ONE, 13, e0200951. DOI: https://doi.org/10.1371/journal.pone.0200951

Jordan, D.S., Gilbert, C.H., 1879. Notes on the fishes of Beaufort Harbor, North Carolina. Proceeding of US National Museum, 1(55), 365-388.

Kajiura, S., Tricas, T., 1996. Seasonal dynamics of dental sexual dimorphism in the Atlantic stingray *Dasyatis sabina*. Journal of Experimental Biology, 199, 2297-2306.

Kent, B.W., 2018. The Cartilaginous Fishes (Chimaeras, Sharks, and Rays) of Calvert Cliffs, Maryland, USA. In: Godfrey, S.J. (ed.). The Geology and Vertebrate Paleontology of Calvert Cliffs, Maryland, USA. Washington D.C., Smithsonian Institution Scholarly Press, 45-161.

Klunzinger, C.B., 1871. Synopsis der Fische des Rothen Meeres II. Theil. Verhandlungen der Königlischen Zoologischen-Botanischen Gesellschaft in Wien, 21, 441-688.

Koot, M.B., Cuny, G., Tintori, A., Twitchett, R.J., 2013. A new diverse shark fauna from the Wordian (Middle Permian) Khuff Formation in the interior Haushi-Huqf area, Sultanate of Oman. Palaeontology, 56(2), 303-343. DOI: https://doi.org/10.1111/j.1475-4983.2012.01199.x

Last, PR., Stevens, J.D., 2009. Sharks and Rays of Australia. Collinwood (Victoria state), Commonwealth Scientific and Industrial Research Organisation (CSIRO) Publishing, 656pp.

Last, P.R., Naylor, G.J.P., Manjaji-Matsumoto, B.M., 2016. A revised classification of the family Dasyatidae (Chondrichthyes: Myliobatiformes) based on new morphological and molecular insights. Zootaxa, 4139, 345-368. DOI: https://doi.org/10.11646/zootaxa.4139.3.2

Leriche, M., 1954. Les faunes ichthyologiques marine du Néogène des Indes Orientales. Mémoires suisses de Paléontologie, 70, 4-21.

Leroy, D., Razin, P., Autin, J., Bache, F., d'Acremont, E., Watremez, L., Robinet, J., Baurion, C., Denèle, Y., Bellahsen, N., Lucazeau, F., Rolandone, F., Rouzo, S., Serra Kiel, J., Robin, C., Guillocheau, F., Tiberi, C., Basuyau, C., Beslier, M.-O., Ebinger, C., Stuart, H., Ahmed, A., Khanbari, K., Al Ganad, I., de Clarens, P., Unternehr, P., Al Toubi, K., Al Lazki, A., 2012. From rifting to oceanic spreading in the Gulf of Aden: a synthesis. Arabian Journal of Geosciences, 5, 859-901. DOI: https://doi.org/10.1007/s12517-011-0475-4

Liu, H., Li, S., Ugolini, A., Momtazi, F., Hou, Z., 2018. Tethyan closure drove tropical marine biodiversity: Vicariant diversification of intertidal crustaceans. Journal of Biogeography, 45, 941-951. DOI: https://doi.org/10.1111/jbi.13183

Hou, Z., Li, S., 2018. Tethyan changes shaped aquatic diversification: Aquatic diversification in the Tethyan region. Biological Reviews, 93, 874-896. DOI: https://doi.org/10.1111/brv.12376

Maiorano, M.P., Marchand, G., Vosges, J., Berger, J., Borgi, J.-F., Charpentier, V., 2018. Sharbithat and the Early-Middle Holocene chronology (Dhofar, Sultanate of Oman). Proceedings of the Seminar for Arabian Studies, 48, 219-234.

Malaquias, M.A.E., Reid, D.G., 2009. Tethyan vicariance, relictualism and speciation: evidence from a global molecular phylogeny of the opisthobranch genus *Bulla*. Journal of Biogeography, 36, 1760-1777.

Marramà, G., Klug, S., Vos, J.D., Kriwet, J., 2018. Anatomy, relationships and palaeobiogeographic implications of the first Neogene holomorphic stingray (Myliobatiformes: Dasyatidae) from the early Miocene of Sulawesi, Indonesia, SE Asia. Zoological Journal of the Linnean Society, 184(4), 1142-1168. DOI: https://doi.org/10.1093/zoolinnean/zly020

Marsili, S., Carnevale, G., Danese, E., Bianucci, G., Landni, W., 2007. Early Miocene vertebrate from Montagna della Maiella, Italy. Annales de Paléontologie, 93, 27-66.

Martin, K., 1883-1887. Beiträge zur Geologie ost-asiens und autraliens, Band III Palaeontologische Ergebnisse von Tiefbohrungen auf Java. Leiden, Samml Geol Reichs-Muss, 330pp.

Mehrotra, D.K., Mishra, VP., Shrivastava, S., 1973. Miocene sharks from India. Recent Researches in Geology, 1, 180-200.

Müller, J., Henle, F.G.J., 1841. Systematische Beschreibung der Plagiostomen. Berlin, Veit, 1-200.

Müller, A., 1999. Ichthyofaunen aus dem atlantischen Tertiär der USA. Leipziger Geowissenschaften, 9-10, 1-360.

Naylor, G.J.P., Marcus, L.F., 1994. Identifying Isolated Shark Teeth of the Genus *Carcharhinus* to Species: Relevance for Tracking Phyletic Change Through the Fossil Record. American Museum Novitates, 3109, 1-53.

Naylor, G.J.P., Caira, J.N., Jensen, K., Rosana, K.A.M., Straube, N., Lakner, C., 2012. Elasmobranch Phylogeny: A mitochondrial Estimate Based on 595 Species. In: Carrier, J.C., Musik, J.A.,
Heithaus, M.R. (eds.). Biology of sharks and their relatives. Boca Raton, Chemical Rubber Company (CRC) Press, second edition, 31-56.

Noetling, F., 1901. Paleontologia Indica, Memoirs of the Geological Survey of India. Calcuta, Geological Survey Office, 1, 1-378.

Otero, O., in press. Fish from the Baynunah Formation (Late Miocene, Abu Dhabi Emirate). Chapter 7. In: Bibi, F., Kraatz, B., Beech, M., Hill, A. (eds.). Sands of time: Late Miocene fossils from the Baynunah Formation, U.A.E. Cham (Switzerland), Springer. Last accessed: February 2022. Website: https://amniota.org/sands-of-time/

Patnaik, R., Sharma, K.L., Mohan, L., Williams, B.A., Kay, R., Chatrath, P., 2014. Additional vertebrate remains from the early Miocene of Kutch, Gujarat. Special Publication of the Palaeontological Society of India, 5, 335-351.

Perez, V.J., Godfrey, S.J., Kent, B.W., Weems, R.E., Nance, J.R., 2019. The transition between *Carcharocles chubutensis* and *Carcharocles megalodon* (Otodontidae, Chondrichthyes): lateral cusplet loss through time. Journal of Vertebrate Paleontology, 38(6), e1546732. DOI: https://doi.org/10.1080/02724634.2018.1546732

Pimiento, C., González-Barba, G., Hendy, A.J.W., Jaramillo, C., MacFadden, B.J., Montes, C., Suarez, S.C., Shippritt, M., 2013. Early Miocene chondrichthyans from the Culebra Formation, Panama: A window into marine vertebrate faunas before closure the Central American Seaway. Journal of South American Earth Sciences, 42, 159-170. DOI: https://doi.org/10.1016/j.jsames.2012.11.005

Pimiento, C., Balk, M.A., 2015. Body-size trends of the extinct giant shark *Carcharocles megalodon*: a deep-time perspective on marine apex predators. Paleobiology, 41, 479-490. DOI: https://doi.org/10.1017/pab.2015.16

Platel, J.-P., Berthiaux, A., Le Métour, J., Beurrier, M., Roger, J., 1992a. Geological map of Duqm and Madraka Sultanate of Oman (Sheet NE 40–03/07, scale 1:250000). Muscat: Oman Ministry of Petroleum and Minerals, Directorate General of Minerals.

Platel, J.-P., Dubreuilh, J., Le Métour, J., Roger, J., Wyns, R., Béchennec, F., Berthiaux, A., 1992b. Geological Map of Juzor Al Halaaniyaat (Sheet NE 40–10/250 000). Muscat: Oman Ministry of Petroleum and Minerals, Directorate General of Minerals.

Pointu, A., 2007. Les mouvements verticaux de la marge passive nord du Golfe d'Aden (Dhofar): causes profondes et superficielles. PhD thesis. Paris, Université Paris VI, 212pp.

Pollerspöck, J., Straube, N., 2021. www.shark-references.com, Version 2021. Last accessed: May 2021. Website: https://shark-references.com/species/listByGenus/136

Priem, M.F., 1907. Note sur les poissons fossiles de Madagascar. Extrait du Bulletin de la société Géologique de France, 4, VII, 462-465.

Priem, R., 1920. Poissons fossiles du Miocène de l'Egypte (Burdigalien de Moghara, Désert Lybique). In: Fourtau, R. (ed.). Contribution à l'étude des Vertébrés miocènes de l'Egypte. Cairo Government Press, 8-15.

Probst, J., 1877. Beiträge zur Kenntniss der fossilen Fische aus der molasse von Baltringen. II: Batoïdei A. Günther. Jahreshefte des Vereins für vaterländische Naturkunde in Württemberg, 33, 69-103.

Probst, J., 1878. Beiträge zur Kenntniss der fossilen Fische aus der molasse von Baltringen. Jahreshefte des Vereins für vaterländische Naturkunde in Württemberg, 35, 113-154.

Purdy, R.W., 1998. The early Miocene fish fauna from the Pollack Farm site, Delaware. In: Benson, R.N. (ed.). Geology and paleontology of the lower Miocene Pollack Farm Fossil Site, Delaware. Delaware Geological Survey, University of Delaware, 133-139.

Purdy, R.W., Schneider, V.P., Applegate, S.P., Mclellan, J.H., Slaughter, R.L., 2001. The Neogene sharks, rays, and bony fishes from Lee Creek Mine, Aurora, North Carolina. In: Ray, C.E., Bohaska, D.J. (eds). Geology and paleontology of the Lee Creek Mine, North Carolina, III, 71-202.

McQuarrie, N., Van Hinsbergen, D.J.J., 2013. Retrodeforming the Arabia–Eurasia collision zone: age of collision versus magnitude of continental subduction. Geology, 41, 315-318.

Rafinesque, C.S., 1810. Caratteri di alcuni nuovi generi e nuove specie di animali e pinate della Sicilia, con varie osservazioni sopra i medisimi. 105pp. Last accessed: February 2022. Website: https://www.biodiversitylibrary.org/item/185076#page/175/mode/1up

Reinecke, T., Von der Hocht, F., Gürs, K., 2008. Die Elasmobranchier des Vierlandiums, Unteres Miozän, im Nordwestdeutschen Becken aus Bohrungen und glaziofluviatilen Geröllen ("Holsteiner Gestein") der Vierlande-Feinsande (Holstein) und der Kakert-Schichten (Niederrhein). Palaeontos, 14, 1-54.

Reinecke, T., Louwye, S., Havekost, U., Moths, H., 2011. The elasmobranch fauna of the late Burdigalian, Miocene, at Werder-Uesen, Lower Saxony, Germany, and its relationships with Early Miocene faunas in the North Atlantic, Central Paratethys and Mediterranean. Palaeontos, 20, 1-170.

Renema, W., Bellwood, D.R., Braga, J.C., Bromfield, K., Hall, R., Johnson, K.G., Lunt, P., Meyer, C.P., McMonagle, L.B., Morley, R.J., O'Dea, A., Todd, J.A., Wesselingh, F.P., Wilson, M.E.J., Pandolfi, J.M., 2008. Hopping hotspots: global shifts in marine biodiversity. Science, 321, 654-657.

Roger, J., Pickford, M., Thomas, H., De Lapparant, F., Tassy, P., Van Neer, W., Bourdillon-de-Grissac, C., Al-Busaidi, S., 1994. Découverte de Vertébrés fossils dans le Miocène de la région du Huqf au Sultanat d'Oman. Annales de Paléontologie (Vert-Invert), 80(4), 253-273.

Sahni, A., Mehrotra, D.K., 1981. The Elasmobranch fauna of coastal Miocene sediments of Peninsular India. Biological Memoires, 5, 83-121.

Santos, R.S., Travassos, H., 1960. Contribuição à Paleontologia do estado do Pará. Peixes fósseis da Formação Pirabas. Rio de Janeiro, Divisão de Geologia e Mineralogia, 16 (Monografia), 35pp.

Segev, A., Avni, Y., Shahar, J., Wald, R., 2017. Late Oligocene and Miocene different seaways to the Red Sea–Gulf of Suez rift and the Gulf of Aqaba–Dead Sea basins. Earth-Science Review, 171, 196-219.
Shimada, K., Becker, M.A., Griffiths, M.L., 2020. Body jaw, and dentition lengths of macrophagous lamniform sharks, and body size evolution in Lamniformes with special reference to ‘off-the-scale’ gigantism of the megatooth shark, *Otodus megalodon*. Historical Biology, 1-17. DOI: https://doi.org/10.1080/08912963.2020.1812598

Soda, K.J., Slice, D.E., Naylor, G.J.P., 2017. Artificial neural networks and geometric morphometric methods as a means for classification: A case-study using teeth from *Carcharhinus* sp. (Carcharhinidae). Journal of Morphology, 278(1), 131-141. DOI: https://doi.org/10.1002/jmor.20626

Tewari, B.S., 1959. On a new fossil shark teeth from the Miocene Beds of Kutch, Western India. Proceedings of the National Institute of Sciences of India, 25, 230-236.

Thomas, H., Sen, S., Khan, M., Battail, B., Ligabue, G., 1982. The Lower Miocene fauna of As-Sarrar (Eastern Province, Saudi Arabia). Atlal, Journal of Saudi Arabian Archaeology, 5(3), 103-136.

Thomas, H., Roger, J., Sen, S., Bourdillon-De-Grissac, C., Al-Sulaimani, Z., 1989. Découverte de vertébrés fossiles dans l'Oligocène inférieur du Dhofar (Sultana d'Oman). Geobios, 22(1), 101-120. DOI: https://doi.org/10.1016/S0016-6995(89)80091-9

Torfstein, A., Steinberg, J., 2020. The Oligo-Miocene closure of the Tethys Ocean and evolution of the proto-Mediterranean Sea. Scientific Reports, 10(1), 13817. DOI: https://doi.org/10.1038/s41598-020-70652-4

Vialle, N., Adnet, S., Cappetta, H., 2011. A new shark and ray fauna from the Middle Miocene of Mazan, Vaucluse (southern France) and its importance in interpreting the paleoenvironment of marine deposits in the southern Rhodanian Basin. Swiss Journal of Palaeontology, 130, 241-258. DOI: https://doi.org/10.1007/s13358-011-0025-4

Ward, D., Bonavia, C.G., 2001. Additions to, and a review of, the Miocene shark and ray fauna of Malta. The Central Mediterranean Naturalist, 3, 131-146.

Welcomme, J.-L., Antoine, P.-O., Duranthon, F., Mein, P., Ginsburg, L., 1997. Nouvelles découvertes de vertebres miocenes dans le synclinal de Dera Bugti (Balouchistan, Pakistan). Comptes Rendus de l'Académie des Sciences, Series IIA, Earth and Planetary Science, 325(7), 531-536.

Woodward, A.S., 1899. Notes on the teeth of sharks and skates from English Eocene formations. Proceedings of the Geologists' Association, 16(1), 1-14. https://doi.org/10.1016/S0016-7878(99)80036-4

Manuscript received May 2021; revision accepted January 2022; published Online March 2022.