Phragmoteuthis polzbergensis, Lukeneder & Fuchs & Lukeneder, 2024

Lukeneder, Petra, Fuchs, Dirk & Lukeneder, Alexander, 2024, Morphology, taxonomy and trophic interactions of rostrum-less coleoids from the Late Triassic Polzberg KonServat-LagerStätte (Lower Austria), Swiss Journal of Palaeontology (21) 143 (1), pp. 1-23 : 13-15

Phragmoteuthis polzbergensis nov sp.

( Figures 7 , 8 , 9 , 11a, b ). non 2022b Phragmoteuthis bisinuata (Bronn) .

Lukeneder & Lukeneder (2022b), p. 273; Figs. 1B , 3 , 4 . non 2007b Phragmoteuthis bisinuata (Bronn) .

Doguzhaeva & Summesberger (2007b), p. 273; Figs. 2 ,

3B–D .

http://zoobank.org/ 46869B54-F172-462D-AE2A-5E2B1 912FAC5

Etymology: Named after the type locality, the Polzberg Konservat-Lagerstätte (Lower Austria).

Holotype: NHMW 2006 z0005/0021 is the only specimen with a proostracum, differentiated arm hooks and a cephalic cartilage preserved.

Type locality and horizon: Reingraben shales at Polzberg main section at 0 cm to − 50 cm, Carnian, Late Triassic.

Material: Eight specimens from recent excavations, at the lowermost 3 m of the Reingraben Shales at Polzberg, from sequence Po − 50 cm to Po 320 cm, inventoried at the NHMW ( NHMW 2021 /0001/0002; NHMW 2021 /0016/0400; NHMW 2021 /0123/0005, 0013, 0057, 0090, 0218, 0424) ; eight specimens from historical NHMW collections; NHMW 2005 z/0005/0021, 0040; NHMW 2012 / 0117/0011, 0025; NHMW 2012 / 0228/0495, 0512; NHMW 2020 / 0033/0003; NHMW 2021 /0124/0038. No mantle remains are preserved. If preserved, the oval-shaped carbonised ink sac is located near the centre of the specimens.

Description: Shell complex: Phragmocones and proostraca are flattened as in the type locality of P. bisinuata ; width measurements and indices are therefore equivocal. Phragmocone lengths range from 14.17 to 22.63 mm, proostracum lengths were measured from 20.41 to 88.31. Te ratio phragmocone length to proostracum length varies between 0.65 and 0.75. Opening angles cannot be determined exactly because of compaction; they range between about 25° and 30°

Sutures appear simple and densely spaced, but statements about septal spacing are speculative.

Te proostracum can be subdivided into a median field and adjacent hyperbolar zones and lateral fields. Te anterior margin of the median field is rounded. Dorsolaterally, the retracted hyperbolar zones are evenly arcuated and occupy c. 83% of the total shell length (ratio hyperbolar zone length to total shell length = 0.83). Te projected lateral fields are likewise evenly rounded and take c. 88% of the total shell length.

Arm complex: NHMW 2021 /0123/0021 stems from the lower, calcareous part of the section and comprises the proostracum, the cephalic cartilage and parts of a differentiated arm crown. Te proostracum of the specimen NHMW 2021 /0123/0090 only appears poorly preserved, but includes the complete arm crown with differentiated hooks, as well as both beaks. Te specimen’s total length is 88.3 mm, with a maximum width of 28.2 mm. Te arm crown of NHMW 2021 /0123/0090 is also preserved in situ and consists of different arm hook types (type 3, 5) .

All of the specimens possess both the stylet shaped (type 3) and curved (type 5) arm hooks ( Fig. 12a ). Closer investigation reveals that the strongly curved hooks preferentially represent at least one modified arm pair, each of them equipped with complementary hook pairs of stylet shaped and curved hooks. Te remaining arms are equipped with the stylet shaped hooks ( Figs. 8 , 9 ).

Head complex: The holotype shows a squashed, but determinable cephalic cartilage of type A. The well preserved cephalic cartilage of specimen NHMW 2012 /0123/0057 with arm hooks identical to those of the holotype and NHMW 2021 /0123/0090 confirms the presence of type A. Further cephalic cartilages of type A are present in specimens NHMW 2021 /0001/0002; NHMW 2012 /0117/0011, 0025; NHMW 2021 /0016/0400 ( Fig. 11a ); NHMW 2021 / 0123/0013, 0424. The carbonised, furcate type of cartilage ( Fig. 11a ; supplementary S1c Figure; Type A cartilage) appears to be a bilaterally symmetric paired structure with a calcite-filled channel system, which follows the geometry of the fossil (see also Lukeneder & Lukeneder, 2022b). It is a distinct, characteristic “C-structure” with a prolonged processus (supplementary S1c Figure). Additional triangularelongate “wing elements” ( Fig. 10a ) are located next to the C-shaped structure .

NHMW 2021 /0123/0013 with the type A cartilage displays a carbonized upper beak illustrating the outline of the inner (lateral wall, crest) and outer lamella (rostrum, hood, wings) .

Figures

Fig. 7 Holotype of P.polzbergensis nov. sp. from the Reingraben shales of the Polzberg Konservat-Lagerstätte. a Specimen includes phragmocone and three-lobed proostracum with a L-shaped cephalic cartilage just anterior to the proostracum. b Detail of furcate cephalic cartilage, exhibiting angular c-structure and slightly curved processus. c Type 2 and type 5 arm hooks are scattered within the area of the cephalic cartilage.cc cephalic cartilage; h hooks;phr phragmocone; pr processus;pro proostracum. Scale bars a 1 cm; b, c 1 mm

Fig. 8 Specimen of P.polzbergensis nov.sp. from the calcareous beds (layer 0, − 50 cm to 0 cm) of the Polzberg section. a NHMW 2021/0123/0090 is one of the most complete phragmoteuthid specimens from recent bed-by-bed collections at the Polzberg Konservat-Lagerstätte. Nine armoured arms, equipped with hooks are visible (compare with Fig. 9, which shows a cumulative reconstruction of the part and counterpart). b Drawing of all preserved elements. Inferred position of the arms are indicated by numbers 1 to 9. Scale bars 1 cm

Fig. 9 Cumulative reconstruction of the arm crown from part and counterpart of P.polzbergensis nov. sp. (NHMW 2021/0123/0090), Hooks associated with nine arms are visible. Black lines part; red lines counterpart; green lines inferred ninth arm; dashed green line arm hooks visible on counterpart.Black rectangle inset: 3D reconstruction of stylet hook type 5; top: anterolateral view, base: ventrolateral view. Scale bar 1 cm. Scale bar hook reconstructions 250 μm

Fig. 11 Phragmoteuthid hooks and cephalic cartilages from the calcareous beds of the Polzberg section.a Furcate cephalic cartilage (type A) and partly preserved arm crown containing differentated arm hooks (NHMW 2021/0016/0400) of P.polzbergensis nov.sp. b Detail showing stylet shaped (type 3) and long-based (type 5) arm hooks. c NHMW 2021/0001/0003 with its differentiated arms exhibiting two hook types (type 3 and type 5). Hooklets point to a phragmoteuthid relationship,without clear species assignment.d Differentiation of arm hooks (type 3, 5) in phragmoteuthid specimen NHMW 2005z/0005/0040. cc cephalic cartilage sensu strico; h hooks; oc ocular cartilage; pl plant remain. Scale bars a, c 1 cm; b, d 1 mm

Fig. 1 Top:Austrian map with the Polzberg Konservat-Lagerstätte (=Schindelberggraben ravine, Polzberg locality) (star, P) and Cave del Predil (northern Italy; formerly: Raibl in Carinthia,Austria) (star, C) marked. Lower left: stratigraphic chart with Bajuvaric Formations and lithological overview log of Polzberg locality. Lower right: middle part of the vrtical section with clays, marls and calcareous deposits of the Reingraben shales at Polzberg. Scale bar 20 cm

Fig. 3 General coleoid hook types from the Polzberg Konservat-Lagerstätte and Cave del Predil. a Curved hook type 1 (NHMW 2021/0123/0216). b Hook type 2 (“megaonychites”) which is commonly only found isolated or within coprolites (NHMW 2021/0123/0213). c Stylet shaped hook type 3 (GBA 2006/011/0001), as it is found in Phragmoteuthis bisinuata. d Curved hook type 4 (NHMW 2006z0235/0001) with curved,splitted base, found in association with specimen of Mojsisovicsteuthis sp.e A curved hook type with a long base (type 5; NHMW 2012/0117/0011). f Abundant coprolites include hook type 1 (NHMW 2021/0123/0227). All scale bars 250 μm

Fig. 4 Mojsisovicsteuthis sp. a NHMW 2005z0005/0028 with low opening angle and characteristic dorsal crest preserved. b Magnification of a, with well-preserved dorsal crest. c NHMW 2012/0228/0515 with dorsal crest preserved and low opening angle of 14.4°. d Phragmocone with dorsal crest and probable remains of ink sac (NHMW 2005z0005/0010).e Poorly preserved dorsal crest of living chamber (NHMW 2012/0228/0561). f Well-preserved dorsal crest in specimen NHMW 2021/0124/0057. g Specimen with non-mineralised last chamber, low opening angle of phragmocone and hooks with a curved base (hook type 4) (NHMW 2005z0005/0027). dc dorsal crest;h arm hooks; is ink sac; phr phragmocone. All scale bars 1 cm

Fig. 2 Evidence for the presence of the Mojsisovicsteuthis sp. from the Polzberg Konservat-Lagerstätte. a Phragmocone with low opening angle in clayey sediment shows a slight yellowish preservation. Note broken or even bitten apex of the phragmocone (NHMW 2021/0124/0047). b Phragmocone with low opening angle, assigned to Mojsisovicsteuthis sp. (NHMW 2005z0005/0039). c Coprolithic specimen NHMW 2021/0123/0197 exhibiting arm hook type 1 and probable megaonychites (type 2). phr phragmocone.Scale bars a, b 1 cm; c 1 mm

Fig. 12 Reconstructions of treated taxa including the most significant features such as size, hook types,phragmocone opening angles. Cephalic cartilages are indicated by purple structures. a P.polzbergensis nov. sp. with type 3 and 5 hooks. b P.bisinuata with type 3 hooks. c Note tubular body chamber and dorsal crest in Mojsisovicsteuthis sp. (hook types 1 and 4). Scale bars 1 cm

Fig. 10 Hooks and cephalic cartilage elements from phragmoteuthid specimens from the Polzberg Konservat-Lagerstätte. a Furcate (type A) cephalic cartilage of Phragmoteuthis polzbergensis nov sp.(NHMW 2012/0117/0025) associated with differentiated stylet and curved shaped coleoid hooks (type 1 and 3). b A massive type of stylet hooks in NHMW 2021/0001/0002, along with a furcate cephalic cartilage.c Type B cephalic cartilage (open ring) associated with ore fragile stylet shaped coleoid hooks (NHMW 2021/0124/0003). d NHMW 2021/0123/0057 with its differentiated arm hooks (thick type 3 hooks and type 5 hooks) and a furcate cephalic cartilage can be assigned to the newly described species P.polzbergensis nov. sp. h hooks; oc ocular cartilage as part of the cephalic cartilage. All scale bars 1 cm