Cretapalibythus moniquae, Charbonnier & Garassino & Brochet, 2025

Cretapalibythus moniquae n. gen., n. sp.

( Fig. 2)

urn:lsid:zoobank.org:act:

DIAGNOSIS. — As for genus.

ETYMOLOGY. — The specific epithet honors Monique Brochet, mother of one of the authors.

TYPE MATERIAL. — Holotype. France • 1 specimen (carapace; adult); Grand-Est, Marne, Cheminon ; Early Cretaceous, early Aptian; Richard Brochet leg.; MNHN. F.A95413 .

TYPE LOCALITY. — Cheminon, Marne, Grand-Est, France.

TYPE AGE. — Early Cretaceous (early Aptian).

DESCRIPTION

Carapace

Elongate, subrectangular carapace not narrowing anteriorly (total length: 17 mm; total width: 9 mm); broad rostrum, wider than long, slightly concave side to side, with pointed extremity; rostral lateral margins marked by a rimmed tuberculate carina ending in a subacute spine; two well-marked tuberculate submedian, post-rostral carinae directed backward as extension of rostral lateral margins, reaching slightly less than half way towards cervical groove; wide orbits with tuberculate orbital margins; large, concave post-orbital margin; one elongate, prominent, unarmed anterolateral spine; carapace weakly constricted at level of cervical groove behind anterolateral spine; straight, unarmed posterolateral margins; deep cervical groove; wide, rounded urogastric region; subtriangular cardiac region narrowing anteriorly; poorly preserved posterior margin as width as frontal margin; dorsal carapace covered with small pits uniformly arranged (as preserved).

DISCUSSION

According to several authors ( Holthuis 1991; Martin & Davis 2001; Lavalli & Spanier 2010; Schweitzer et al. 2015), the Achelata are subdivided into four families: Cancrinidae Beurlen, 1930 , Palinuridae Latreille,1802 , Scyllaridae Latreille,1825 , and Synaxidae . Extant synaxid lobsters, including only two genera ( Palibythus Davie, 1990 and Palinurellus von Martens, 1878 ), are easily differentiated from palinurid lobsters in that they lack frontal supra-orbital horns. However, according to Fraaije et al. (2023), synaxids bear a prominent, broad-based rostrum, a tapered carapace, not depressed or flattened, but tubular, and the anterior part of carapace (rostrum to cervical groove) exceeds the posterior one (cervical groove to posterior margin) in length. Moreover, synaxid lobsters differ from scyllarid lobsters in having a long and broad triangular rostrum and a tapered anterior carapace that is not depressed.Finally,synaxid lobsters differ from cancrinid lobsters in having short antennal flagella.

According to Holthuis (1991: 90) the members of Synaxidae have carapaces lacking frontal horns, but with a large, broad, and flat rostrum, and the dorsal surface covered only with granules or tubercles. Cretapalibythus n. gen. fits the main characters of this family to which it is assigned.

The representatives of the Synaxidae are rare components of extant benthic communities, as reported by Holthuis (1991). The fossil record of the family is instead more common, especially from reefal settings of Late Jurassic age in Europe with Palaeopalinurellus culocervus Fraaije, Van Bakel, Jagt & Brochet, 2020 (Oxfordian, France), Palaeopalinurellus strambergensis Bachmayer, 1959 (Tithonian, Czech Republic), and Palaeosynaxes montserratae Fraaije, van Bakel, Jagt, Krobicki, Ossó, Palero& Wallaard,2023 (Oxfordian, Poland). Palaeopalinurellus jbeilensis Garassino & Pasini, 2020 (Cenomanian, Lebanon) is the first record of Palaeopalinurellus out of Europe and the sole species from the Late Cretaceous . Finally, Palinurellus bericus De Angeli & Garassino, 2014 (Priabonian, Italy) is the so far oldest fossil species of the extant genus Palinurellus .

Cretapalibythus n. gen. differs from Palaeopalinurellus and Palaeosynaxes in having the dorsal carapace covered with small pits uniformly arranged (vs anterior part with irregularly tuberculate, posterior part densely covered with scale-like tubercles in Palaeopalinurellus and carapace densely covered with coarse, blunt, forwardly directed tubercles in Palaeosynaxes ). It differs from Palinurellus in having a rostrum wider than long and tuberculate post-rostral carinae (vs rostrum longer than wide without post-rostral carinae in Palinurellus ).

Based on Davie (1990), Cretapalibythus n. gen. shares with the extant Palibythus the rostrum wider than long and the tuberculate post-rostral carinae. However, besides its smaller size, the studied specimen differs from Palibythus in having unarmed, rimmed, rostral lateral margins (vs rostral lateral margin with several spines in Palibythus ) and just one elongate, prominent, unarmed anterolateral spine (vs anterolateral spines with several spines in Palibythus ). Based on these observations, Cretapalibythus n. gen. represents the first report of a furry lobster from the Early Cretaceous , filling the gap between the Late Jurassic and Late Cretaceous synaxid lobsters. Finally, it represents the second report of a fossil synaxid lobster from France after the report of the Late Jurassic (Oxfordian) Palaeopalinurellus culocervus by Fraaije et al. (2020).