Funeralaspis deathvalleyensis, Adrain & Pérez-Peris, 2023

Adrain, Jonathan M. & Pérez-Peris, Francesc, 2023, Funeralaspis n. gen.: a new odontopleurine trilobite from the early Middle Ordovician (Dapingian) of Death Valley, eastern California, USA, and the classification of Ordovician odontopleurines, Zootaxa 5336 (4), pp. 509-529 : 513-521

Funeralaspis deathvalleyensis n. sp.

Figures 1–5 , 6.1–6.33, 6.35–6.38, 6.41, 6.42

1967 Diacanthaspis spp. ; Ross, p. D30, pl. 9, figs 29–34.

1967 Odontopleurid trilobite indet.; Ross, p. D30, pl. 9, figs 36–39.

Material. Holotype, cranidium, SUI 148653 ( Fig. 1.3, 1.6, 1.9, 1.13 ) and assigned specimens SUI 148651 , 148652 , 148654–148698 , from the Antelope Valley Formation (Dapingian), west flank of Funeral Mountains , Death Valley National Park, Inyo County, eastern California, USA.

Etymology. From Death Valley.

Diagnosis. As the genus is monotypic, see genus diagnosis.

Description. Cranidial measurements are based on the specimens of Figure 1 (1.1, 1.2, 1.3) and Figure 2 (2.1, 2.2, 2.3). Cranidium subtrapezoidal in outline, wider (tr.) posteriorly, maximum width (tr.) across posterior border, dramatically narrower (tr.) anterior to the posterior border, gently narrowing (tr.) anteriorly from medial part of the palpebral lobe, with length (sag.) 54% (49–55%) maximum width (tr.), dorsally vaulted with maximum inflation at occipital ring ( Figs 1.11, 1.12, 1.13 , 2.7, 2.8, 2.16 ), medial glabellar lobe slightly vaulted dorsally ( Figs 1.7 , 2.4, 2.5, 2.6 ) fixigenal field and posterior border abaxially downturned from horizontal, in lateral view slightly sloping downwards forward, anterior to S2 strongly downturned from horizontal ( Figs 1.11 , 2.24 ); anterior border transverse (e.g., Figs 1.7 , 2.5 ), short (sag.) medially, increasing length (exsag.) laterally, transverse from horizontal, anterolateral corners gently rounded, densely sculped by small tubercles; anterior border furrow bowed anteriorly, longer (exsag.) distally, shortening (sag.) proximally, relatively well incised; glabella suboval in outline, with length (sag.) 93.5% (87–103%) maximum width (tr.) across the anterior half of L1, narrowing (tr.) forward, anterolateral corners rounded, posterolateral corners pointed but slightly rounded, anterior margin of the glabella arched anteriorly, posterior margin transverse medially slightly arched anteriorly, surface densely covered by tubercles of different sizes, coarse tubercles more densely arranged at glabellar lobes, medial part and especially the anterior lobe (e.g., Fig. 2.1 ); S1 relatively long (exsag.), deeply incised abaxially, shallowing adaxially, forming a shallow depression, distally running posteromedially approximately 35 degrees from the axial furrow, adaxially curving posteriorly, proximal terminal part posteriorly directed with the most posterior part gently turned outwards, in contact with SO by a shallow depression (e.g. Fig. 2.3 ); S2 slightly shorter (exsag.) than S1, width (tr.) similar to S1, subparallel to S1, running posteromedially from the axial furrow, proximally turning posteriorly, deeply incised abaxially, shallowing adaxially to become a faint depression that separates L2 from the medial glabellar lobe (e.g., Fig. 1.1 ); SO deep and short (exsag.) laterally, longer (sag.) medially, directed slightly posteromedially distally, medial part shallow, present as a faint depression that separates the medial glabellar lobe and LO, proximally transverse slightly bowed anteriorly; LO relatively long (sag. and exsag.), with maximum length sagittally, posterior margin greatly bowed posteriorly, anterior margin laterally directed posteromedially and medially slightly bowed anteriorly, densely covered by small and medium tubercles, sagittally carrying a distinctly larger median occipital lobe (e.g., Figs 1.3 , 2.1 ), posterior margin with two paired spines (e.g., Figs 2.2, 2.3 ), directed backwards, with rounded tip; L1 suboval in shape, longer (exsag.) and wider (tr.) than L2, proximally weakly isolated from medial glabellar lobe by faint S1 and anterolaterally weakly isolated from fixigenal field by a shallow axial furrow, anterior margin greatly bowed anteriorly and slightly outwards, posterior border transverse gently bowed posteriorly; L2 shorter (exsag.) and narrower (tr.) than L1, subcircular in shape, proximally separated from medial lobe by a faint and shallow S2, distally weakly separated from the fixigenal field by a shallow axial furrow; L3 obscure, in some specimens with potential independent inflation ( Fig. 2.1 ), but often indistinguishable from the frontal lobe; axial furrow narrow (tr.), deeply incised across the posterior part of L1, shallowing forwards almost effacing, outwardly bowed with the maximum curvature across anterior part of L1, posteriorly to L1 running obliquely posterolaterally from the lateral corner of L1 to the proximal part of the border furrow, really shallow, expressed as a faint depression; interocular fixigenal field long (exsag.), extremely narrow (tr.), slightly wider (tr.) posteriorly, with maximum width (tr.) across the palpebral lobe, outer margin bowed outwardly with maximum curvature at the palpebral lobe ( Fig. 2.1 ); posterior part of the fixigenal field subtriangular in outline, wide (tr.), proximally short (exsag.), shortening (exsag.) distally with the most distal part extremely reduced ( Fig. 2.1 ), anterior margin distally running outwards and backwards; posterior border furrow narrow (exsag.), adaxially slightly longer (exsag.), abaxially directed outwards and backward; posterior border relatively long (exsag.), shorter (exsag.) proximally, slightly longer (exsag.) distally, inner part almost transverse, lateral part beyond the palpebral lobe gently bending posteriorly, distal corner rounded, smooth with few sparse small to medium tubercles more densely arranged distally; palpebral lobe set opposite posterior half of L1 with outer margin strongly convex laterally, and inner margin gently convex laterally, anterior part continuous with eye ridge; eye ridge long (exsag.) and narrow (tr.), gently narrowing (tr.) anteriorly, running forward and slightly inward from the anterior tip of the palpebral lobe, strongly bending inward at the intersection with the anterior lobe of the glabella ( Figs 1.7, 1.9, 1.24 , 2.2, 2.6 ); palpebral lobe and eye ridge covered with dense coarse tubercles similar in size to the glabellar tubercles (e.g., Fig. 2.1 ); palpebral furrow narrow (tr.), relatively shallow, running from the posterior tip of the palpebral lobe forward along the eye ridge, to the intersection with the axial furrow opposite S2; anterior branch of the facial suture runs from the anterior margin backwards slightly outwardly oriented, opposite posterior half of L1, describing an outwardly directed arc, ending at the base of the palpebral lobe opposite SO; posterior branch of the facial suture abaxially gently curving posterolaterally, most distal part dramatically turning posteriorly across the posterior border; doublure long (sag.) beneath LO ( Figs 1.4, 1.5 ), anterior margin greatly bowed forward, posterior more gently bowed backward, smooth; doublure also present beneath the distal part of the posterior border (e.g., Fig. 1.6 ), short (exsag.) proximally, longer (exsag.) distally, reaching almost the same length as the posterior border, most distal part subtriangular in outline, smooth.

Librigenal measurements were made on specimens of Figure 3 (3.1, 3.2, 3.4, 3.6, 3.13, 3.15). Librigenal field subtriangular in outline, length (exsag.) along the lateral border furrow 151% (139–166%) maximum width (tr.), shorter (exsag.) proximally along the eye lobe margin, longer (exsag.) distally along the border furrow, distally sloping downwards from horizontal ( Figs 3.3, 3.10 ), bordered by anterior and posterior sutural ridges, sculpted by small size granules, proximal half bearing bigger size tubercles densely arranged; anterior ridge really short (exsag.); posterior ridge proximally short (exsag.), distally longer (exsag.) and subquadrate in shape, merging smoothly with the base of the genal spine (e.g. Fig. 3.1 ); eye lobe relatively large, suboval in shape, set obliquely, posterior margin posteriorly bowed; lateral border furrow shallow, narrow (tr.) forward, widening (tr.) backwards, with maximum width (tr.) at the intersection with the posterior border furrow, gently bowed outwardly; anterior border furrow very short (exsag.) and shallow, proximally barely discernible, slightly longer (exsag.) distally with maximum width with the intersection with lateral border furrow; posterior border furrow short (exsag.) proximally, longer (exsag.) distally across the longer (exsag.) part of the posterior ridge, proximal two thirds running backwards and outwards and describing a faint anterolaterally directed arc, distal part outwardly directed and almost transverse; lateral border relatively wide (tr.), with a maximum width (tr.) 24.3% (23–28%) total width (tr.) of the librigena (excluding the eye lobe and the border spines), narrower (tr.) anteriorly, slightly expanding (tr.) posteriorly, with the maximum width (tr.) across posterior sutural ridge, outwardly bowed, anteriorly extended into a narrow (tr.) and short (exsag.) projection (e.g., Figs 3.1, 3.6., 3.14 ), subtriangular in shape, slightly directed outwards, posteriorly extended into a long genal spine similar in length (exsag.) to the rest of the librigena, backwardly directed, gently inwardly curved, distal tip pointed, circular in outline; lateral border with typically 11 border spines (e.g., Fig. 3.15 ), with variation from 10 (e.g., Fig. 3.12 ) to 12 (e.g., Fig. 3.10 ), anterior spines very small, expressed as small bumps, increasing in size posteriorly, five posterior spines of similar size, rounded tip, subcircular in cross section, running backwards outwardly; doublure beneath the lateral border ( Figs 3.5, 3.9 ), anterior projection, and the distal part of the posterior border, similar in width (tr.) to the lateral border, outwardly bowed; lateral, anterior and posterior ridge densely sculpted by small granules, posterior part of the lateral border and genal spines carrying medium size granules.

Rostral plate unknown.

Hypostomal measurements were made on specimens of Figure 4 (4.1–4.4). Hypostome subquadrate in outline, with sagittal length 79.8% (75–84%) maximum width (tr.), maximum width (tr.) across anterior wings, similar width (tr.) across posterior wings, flat, gently vaulted ventrally anteriorly medially ( Figs 4.6, 4.7 ); anterior border almost transverse, slightly bowed medially anteriorly, very short (sag.) adaxially, slightly lengthening (exsag.) abaxially, sagittally partially overlapped by the anterior lobe of the hypostome middle body, merging smoothly with lateral wings; anterior border furrow shallow, slightly bowed anteriorly, short (sag.) medially, overlapped by anterior lobe of the hypostome body, expanding (exsag.) laterally; anterior wings short (exsag.), subtriangular in shape, slightly extended beyond the lateral shoulder, wing process extended dorsally; posterior wings smaller than anterior wing, extended inwards and slightly dorsally directed ( Fig. 4.7 ); middle body ovoid in shape, with length (sag.) 94.5% (88–100%) width (tr.), anterior lobe longer (sag.) than posterior lobe, similar in width (tr.), gently vaulted ventrally anteriorly; anterior lobe subcircular in shape, anterior margin slightly bowed forward, wider (tr.) anteriorly, tapering (tr.) posteriorly, posterior margin weakly defined, arched posteriorly; posterior lobe U-shaped, bowed backwards, longer (sag.) medially, shortening (exsag.) laterally; middle furrow faint, effaced, really shallow, difficult to identify, bowed posteriorly; maculae reduced, narrow (tr.), posteromedially directed; border furrow well defined, deeply incised, slightly deeper anteriorly across the anterior lobe of the middle body, slightly shallowing posteriorly; lateral border narrower (tr.) anteriorly, slightly expanding (tr.) posteriorly across the shoulder; posterior border relatively long (sag.), longer than lateral border, posterior margin greatly bowed posteriorly with medial part almost transverse, margin smooth, in posterior view medial part gently dorsally concave ( Figs 4.9, 4.11 ); densely sculpted of medium size granules, bigger granules in the anterior part of the anterior lobe; doublure beneath the lateral and posterior border, slightly narrower (tr.) and shorter (sag.), smooth.

Thoracic measurements were taken on specimens of Figure 5 (5.1, 5.2). Segment count unknown; articulating half-ring suboval in outline, relatively long (sag.) medially, with sagittal length (sag.) 42% (41–43%) thoracic segment sagittal length, laterally shorter (exsag.), anterior border strongly bowed anteriorly, posteriorly border bowed posteriorly, almost transverse medially, in anterior view strongly arched dorsally (e.g., Figs 5.3, 5.7, 5.9 ); articulating furrow long (sag.), shorter (exsag.) laterally, relatively shallow, slightly arched posteriorly; axial ring subrectangular in outline, slightly wider (tr.) than articulating half-ring, wider (tr.) anteriorly gently narrowing (tr.) posteriorly, dorsally highly vaulted (e.g., Fig. 5.3 ), anterior and posterior margin slightly bowed posteriorly, lateral margins slightly bowed outwardly; axial furrow narrow (tr.), shallow, gently bowed outwardly; articulating flange present along anterior and posterior margin of the pleurae, anterior flange wider (tr.) than posterior, running transversely from the intersection of the axial furrow to the fulcrum ( Figs 5.1, 5.2, 5.13 ), very short (exsag.), slightly expanding (exsag.) distally, longest (exsag.) at fulcrum, lateral corner rounded, posterior flange very short (exsag.) ( Fig. 5.2 ), running from the intersection with the axial furrow to base of the posterior pleural spine; thoracic pleurae divided into anterior and posterior band by pleural furrow; pleural furrow deeply incised, short (exsag.), slightly expanding abaxially (exsag.), adaxially gently backwards directed, medial part almost transverse, abaxially posteriorly bending; anterior band shorter (exsag.) than posterior band, shorter (exsag.) proximally, gently lengthening (exsag.) distally, anterior margin transverse adaxially, bending posteriorly at fulcrum, extending into a short pleural spine abaxially (e.g., Fig. 5.12 ), spine strongly bending backwards, narrowing (tr.) distally, pointed distal tip; posterior pleural band long (exsag.), anterior and posterior margin proximally transverse, distally slightly bending backwards, laterally extending into a thoracic pleural spine, spine considerably longer and wider (tr.) than anterior thoracic spine, posteriorly tapering (tr.), strongly curving backwards, distal part slightly downturned from horizontal ( Figs 5.12, 5.15 ), pointed distal tip, circular in outline; doublure beneath the axial ring long (sag.) ( Figs 5.4, 5.5 ), anterior margin bowed forward, posterior margin transverse, shorter (exsag.) laterally, smooth; doublure at fulcrum set obliquely (e.g. Fig. 5.5 .), posteromedially directed, narrow (tr.), subrectangular in outline, carrying small granules; surface densely sculpted with small to medium size granules, anterior pleural band more densely sculpted than posterior band, medium size granules more densely distributed at posterior thoracic pleural spine, axial ring bearing a pair of granules more prominent than the rest ( Figs 5.7, 5.13, 5.14 ), prominent tubercle at the base of each posterior pleural spine comparable in size to the axial ring tubercles ( Figs 5.3, 5.7, 5.13, 5.14 ).

Pygidial measurements taken on specimens of Figure 6 (6.1, 6.5, 6.16). Pygidium semi-circular (excluding the pygidial pleural spines), relatively short (sag.), with total sagittal length (excluding articulating half-ring and pleural spines) 29% (28–30%) maximum width (tr.), maximum width (tr.) forward, tapering backwards, five pairs of pygidial pleural spines present, dorsoventrally flat with anterior axial part slightly vaulted dorsally (e.g. Figs 6.6, 6.13 ); articulating half-ring suboval in outline, relatively long (sag.) proximally, shortening distally (exsag.), anterior margin bowed anteriorly, posterior margin slightly bowed posteriorly with medial part almost transverse, dorsally convex (e.g. Fig. 6.18 ), sculpted by tiny granules; articulating furrow short (sag., exsag.), deeply incised, well defined, slightly bowed posteriorly; axis semi-ovoid in outline, composed by two axial rings and a reduced terminal piece ( Figs 6.1, 6.2, 6.9 ), wider (tr.) anteriorly, tapering (tr.) posteriorly, vaulted anteriorly, slightly flattening posteriorly, with most posterior part flat; first axial ring subrectangular in shape, anterior margin almost transverse slightly bowed posteriorly, posterior margin transverse slightly bowed anteriorly, corners gently bowed outward; second axial ring subtrapezoidal in shape, slightly shorter (sag.) and narrower than first axial ring, tapering (tr.) backwards, anterior margin transverse, slightly wider (tr.) than posterior margin, posterior margin transverse; terminal piece extremely reduced, very short (sag.), slightly narrower than second axial ring, posterior margin bowed posteriorly; first inter-ring furrow short (sag.), transverse, well defined, deeply incised, slightly shallowing medially; second inter-ring furrow short (sag.), transverse, very shallow and almost effaced; axial furrow short (sag.), relatively shallow, shallowing across first axial ring becoming almost effaced; two pairs of lateral spines directed posteriorly and slightly outwardly, dorsoventrally horizontal (e.g., Figs 6.17, 6.20 ), anterior pair slightly shorter (exsag.) than posterior, circular in cross section; major border spines longer (exsag.) and wider (tr.) than lateral and medial spines, directed backwards and gently outwards, subtly curving medially, distal part directed slightly dorsally ( Fig. 6.10 ), circular in cross section; pleural ridge strongly bended posteriorly, proximally set opposite to the first axial ring, distally extended into the major border spine; two pair of medial spines similar in length (sag.) and width (tr.) to the posterior lateral spine, subparallel, strongly directed backwards subtly outwardly, circular in cross section; surface densely sculpted with middle size granules, major border spines carrying bigger size tubercles, pair of big tubercles sculpted in each axial ring, prominent tubercle on pleural region in front of second pair of pygidial spines; posterior margin of the pygidium greatly bowed posteriorly, running ventrally to the pygidial spines ( Figs 6.3, 6.4, 6.23 ), strongly flexed downwards; doublure relatively long (sag., exsag.), slightly longer (sag.) sagittally, running along the posterior margin of the pygidium, strongly flexed dorsally ( Fig. 6.7 ), smooth, outwardly densely sculpted with small granules more densely arranged medially.

Discussion. A single librigena ( Fig. 3.7 ) differs from all of the others in the possession of a very short, thorn-like genal spine. We interpret this specimen as teratological, possibly representing a healed injury.

Figures

FIGURE 1. Funeralaspis deathvalleyensis n. gen. n. sp., from the Antelope Valley Formation (Dapingian), west flank of Funeral Mountains, Death Valley National Park, Inyo County, eastern California, USA. 1, 4, 7, 10, 11. Cranidium, SUI 148651, dorsal, ventral, anterior, oblique, and left lateral views, x15. 2, 5, 8, 12. Cranidium, SUI 148652, dorsal, ventral, anterior, and left lateral views, x12. 3, 6, 9, 13. Cranidium, holotype, SUI 148653, dorsal, ventral, anterior, and right lateral views, x15. 14, 21, 24. Cranidium, SUI 148654, dorsal, left lateral, and anterior views, x12. 15, 18, 22. Cranidium, SUI 148655, dorsal, anterior, and right lateral views, x12. 16, 19. Cranidium, SUI 148656, dorsal and right lateral views, x12. 17, 20, 23. Cranidium, SUI 148657, dorsal, anterior, and right lateral views, x12. 25–27. Cranidium, SUI 148658, anterior, right lateral, and dorsal views, x30.

FIGURE 2. Funeralaspis deathvalleyensis n. gen. n. sp., from the Antelope Valley Formation (Dapingian), west flank of Funeral Mountains, Death Valley National Park, Inyo County, eastern California, USA. 1, 4, 7. Cranidium, SUI 148659, dorsal, anterior, and right lateral views, x15. 2, 5, 8, 9. Cranidium, SUI 148660, dorsal, anterior, left lateral, and oblique views, x15. 3, 6, 12, 16. Cranidium, SUI 148661, dorsal, anterior, oblique, and right lateral views, x15. 10, 11, 13. Cranidium, SUI 148662, dorsal, right lateral, and anterior views, x17. 14, 15, 20. Cranidium, SUI 148663, left lateral, dorsal, and anterior views, x17. 17–19. Cranidium, SUI 148664, dorsal, anterior, and left lateral views, x12. 21, 23, 24. Cranidium, SUI 148665, anterior, dorsal, and left lateral views, x12. 22, 25, 26. Cranidium, SUI 148666, anterior, left lateral, and dorsal views, x12.

FIGURE 3. Funeralaspis deathvalleyensis n. gen. n. sp., from the Antelope Valley Formation (Dapingian), west flank of Funeral Mountains, Death Valley National Park, Inyo County, eastern California, USA. 1, 3, 5. Right librigena, SUI 148667, external, ventrolateral, and internal views, x12. 2. Right librigena, SUI 148668, external view, x15. 4. Left librigena, SUI 148669, external view, x12. 6, 9, 10. Left librigena, SUI 148670, external, internal, and ventrolateral views, x15. 7. Right librigena, SUI 148671, external view, x15. 8. Right librigena, SUI 148672, external view, x20. 11. Right librigena, SUI 148673, external view, x15. 12. Right librigena, SUI 148674, external view, x15. 13. Left librigena, SUI 148675, external view, x15. 14. Right librigena, SUI 148676, external view, x15. 15. Left librigena, SUI 148677, external view, x15. 16. Right librigena, SUI 148678, external view, x15.

FIGURE 4. Funeralaspis deathvalleyensis n. gen. n. sp., from the Antelope Valley Formation (Dapingian), west flank of Funeral Mountains, Death Valley National Park, Inyo County, eastern California, USA. 1, 5, 9, 13, 15. Hypostome, SUI 148679, ventral, right lateral, posterior, dorsal, and anterior views, x20. 2, 6, 10, 14. Hypostome, SUI 148680, ventral, left lateral, posterior, and anterior views, x20. 3, 7, 11, 16, 18. Hypostome, SUI 148681, ventral, left lateral, posterior, dorsal, and anterior views, x25. 4, 8, 12, 17. Hypostome, SUI 148682, ventral, right lateral, posterior, and anterior views, x25.

FIGURE 5. Funeralaspis deathvalleyensis n. gen. n. sp., from the Antelope Valley Formation (Dapingian), west flank of Funeral Mountains, Death Valley National Park, Inyo County, eastern California, USA. 1, 3, 5, 6. Thoracic segment, SUI 148683, dorsal, anterior, ventral, and right lateral views, x15. 2, 4, 7, 9, 12. Thoracic segment, SUI 148684, dorsal, ventral, anterior, posterior, and right lateral views, x15. 8, 10, 13, 14. Thoracic segment, SUI 148685, left lateral, dorsal, anterior, and posterior views, x15. 11, 16, 18, 21. Thoracic segments, SUI 148686, right lateral, dorsal, anterior, and posterior views, x20. 15, 17, 19, 20. Thoracic segment, SUI 148687, right lateral, anterior, dorsal, and posterior views, x15.

FIGURE 6. 1–33, 36–38, 41, 42. Funeralaspis deathvalleyensis n. gen. n. sp., from the Antelope Valley Formation (Dapingian), west flank of Funeral Mountains, Death Valley National Park, Inyo County, eastern California, USA. 1, 6–8, 14. Pygidium, SUI 148688, dorsal, posterior, anterior, ventral, and left lateral views, x15. 2–4. Pygidium, SUI 148689, dorsal, right lateral, and posterior views, x15. 5, 10, 12, 15, 18. Pygidium, SUI 148690, dorsal, right lateral, ventral, posterior, and anterior views, x15. 9, 13, 17. Pygidium, SUI 148691, dorsal, posterior, and left lateral views, x17. 11, 21, 22. Pygidium, SUI 148692, left lateral, posterior, and dorsal views, x20. 16, 19, 20. Pygidium, SUI 148693, dorsal, posterior, and right lateral views, x17. 23, 26, 30. Pygidium, SUI 148694, right lateral, dorsal, and posterior views, x25. 24, 27, 31. Pygidium, SUI 148695, dorsal, posterior, and right lateral views, x25. 25, 28, 29, 33. Pygidium and thoracic segments, SUI 148696, dorsal, right lateral, posterior, and ventral views, x15. 32, 36, 37. Pygidium, SUI 148697, dorsal, left lateral, and posterior views, x15. 38, 41, 42. Pygidium, SUI 148698, dorsal, left lateral, and posterior views, x15. 34, 35, 39, 40.?acidaspidine pygidium, SUI 148699, dorsal, ventral, posterior, and right lateral views, x15.