The Cambrian (Paibian – Jiangshanian; Steptoean) dokimocephalid trilobite Deckera Frederickson, 1949 in Laurentian North America

Non-technical Summary. — New samples of Deckera , an uncommon genus of trilobites, show that it is widespread in marine Cambrian rocks of North America in the range of ∼ 492 – 494 million years old. It could be represented by as many as nine species. The genus was originally de ﬁ ned in part by eyes that are elevated at or above the crest of the head region, but the oldest species are characterized by eyes that are much lower. All species share a relatively wide head region, which is now the most important diagnostic characteristic of Deckera . Abstract. — The Cambrian dokimocephalid trilobite genus Deckera Frederickson, 1949 is a minor component of Step-toean (Jiangshanian) faunas of Laurentian North America. The original diagnosis emphasized strongly in ﬂ ated palpebral areas of ﬁ xed cheeks and elevated palpebral lobes as important and novel characters. An appraisal of archival and new specimens from Oklahoma, Missouri, Pennsylvania, Nevada, Utah, and Newfoundland show that the genus is geographically widespread and likely represented by as many as nine species, although only two of them are named formally. Deckera cf. D . aldenensis Frederickson, 1949 from Nevada extends the stratigraphic range of Deckera down to the base of the Jiangshanian Stage, and new species from Nevada and Newfoundland take the genus down farther, into upper Paibian strata. Paibian species show that some basal members of the genus have weakly in ﬂ ated, nearly ﬂ at palpebral areas with palpebral lobes that sit well below the crest of the glabella. A revised diagnosis of Deckera focuses on the broad cranidium with width across the palpebral lobes much greater than the sagittal length. Pygidia are


Introduction
Deckera Frederickson, 1949 was named for a single figured cranidium from the Honey Creek Formation (Jiangshanian; Steptoean; Elvinia Biozone) from Oklahoma and was reported soon afterward from the coeval Gatesburg Formation of Pennsylvania (Wilson, 1951) with a larger sample that included a pygidium and librigena.However, the ensuing 50 years added only a handful of cranidia from Wyoming (Lochman and Hu, 1960), Oklahoma (Stitt, 1971), and Missouri (Kurtz, 1975), so that the genus remains at best a minor component of Elvina Zone faunas of Laurentian North America.
Discovery of sclerites of two species from Nevada and Utah prompted restudy of type and new material of Deckera aldenensis Frederickson, 1949 from Oklahoma and the types of Deckera completa Wilson, 1951 from Pennsylvania.In addition, a few new specimens from Nevada and Newfoundland extend the range of Deckera down into Paibian strata and provide new information of character states of basal members of the clade.Although unquestionably rare, the new material documented in this paper show that Deckera is surprising diverse and has some biostratigraphic utility.There could be as many as nine species in Steptoean strata of Laurentia, although small sample sizes prevent most of them from being named formally.This paper also continues a long-term project revising the diverse agnostid and trilobite faunas of the Elvinia Zone of the Great Basin and Oklahoma (Westrop et al., 2007(Westrop et al., , 2008(Westrop et al., , 2010;;Westrop and Adrain, 2009a, b, 2013, 2016).

Study areas and stratigraphic settings
The revision of Deckera makes use of type and other archival material from Oklahoma, Missouri, and Pennsylvania, and new specimens from Oklahoma, Nevada, Utah, and Newfoundland.that yielded this species are from Ring Top Mountain (Fig. 1.4; 34°51 ′ 1"N, 98°31 ′ 40"W), ∼4.7 km north of locality 6.The succession was measured and logged as three stratigraphic sections (sections KR1, KR2, and KR3) that were correlated physically by pacing out a conspicuous carbonate marker bed around the western slopes of the hill (see Westrop et al., 2010, fig. 1, for locations and lithologic logs of the Elvinia Zone segments of the three sections and their correlation).A sample from section KR2 (KR2 50.3) that yielded Deckera, including Deckera aldenensis, was collected near the top of the marker bed, which comprises glauconitic, rippled bioclastic grain-and-rudstone with thin siliciclastic drapes.Associated species included Dokimocephalus intermedius (Resser, 1942) (see Westrop et al., 2010, fig. 1), Camaraspis convexa (Whitfield, 1878), Dellea cf.D. suada Wilson, 1949, and Pterocephalia sanctisabae Roemer, 1849.The highest occurrences of Plataspella Wilson, 1949(Westrop et al., 2010, fig. 1) and Kindbladia Frederickson, 1948(unpublished data, Westrop, 2024) are < 1 m below the sample horizon.This places Deckera aldenensis at the base of an informal upper division (Stitt, 1977;Westrop et al., 2007) of the Elvinia Zone that directly underlies the Irvingella 'major' Zone (Fig. 2).Deckera cf.D. completa (see Systematic paleontology section) occurred with Deckera aldenensis in collection KR2 50.3, and restudy of Frederickson's (1949, p. 345) material from his locality 9 in Kiowa County (which is the same locality as section BM of Blackwell and Westrop, 2023, fig. 1) yielded the same association.
The underlying Dunderberg Formation at CHC-2 is a 203 m thick succession of shale and carbonate that forms a recessive slope below the Barton Canyon Limestone Member.A single cranidium of Deckera new species 1 was recovered from a small collection made 138.5 m above the base of the formation.It lies in the Paibian Dunderbergia Zone (Fig. 2), 13 m below the base of Elvinia Zone, as marked by the lowest occurrence of Housia ovata Palmer, 1960 at 151.5 m in the section.
Utah.-The upper Orr Formation was studied at Orr Ridge (section ORR) in the northern House Range, Millard County, Utah (Fig. 1.1).The section was measured and logged on a NE-SW trending ridge that forms the southern side of Big Horse Canyon; the type section of the Orr Formation (Hintze and Palmer, 1976) is on the ridge immediately to the north.It was measured from the base of the Corset Spring Shale Member.At Orr Ridge, this member forms a recessive slope above the cliff-forming Johns Wash Limestone Member.It includes a poorly exposed, basal 8 m interval of green shale with minor carbonates that records a lowstand (Evans et. al., 2003;Miller et al., 2012).Collection ORR 7.5 is a float sample from near the top of this interval and yielded rare cranidia of Deckera cf.D. aldenensis (Fig. 2).Associated with Deckera cf.D. aldenensis in this collection were Irvingella angustilimbata Kobayashi, 1938 (see Westrop andAdrain, 2016); Bynumina globosa (Walcott, 1884) (see Westrop et al., 2007); Pseudokingstonia exotica Palmer, 1965 (see Westrop andAdrain, 2009b); Kindbladia cf.K. affinis; as well as undescribed species of Dellea and Pseudosaratogia that also occur in collection CHC-2-203.1 at Barton Canyon, Nevada (see above).As in the occurrence in collection CHC-2-203.1,this assemblage also placed Deckera cf.D. aldenensis in the lower informal division of the Elvinia Zone.From its position in the Corset Spring Shale with I. angustilimbata, it extends the range of the genus down toward the base of the zone and the base of the Jiangshanian Stage.
Pennsylvania.-Ourstudy is restricted to the type specimens of Deckera completa from the Ore Hill Member of the Gatesburg Formation.Loch andTaylor (1995, 2004;Taylor et al., 1999) restudied the Ore Hill Member at several of Wilson's (1951) localities, and their measured sections (Taylor et al., 1999, fig. 2;Loch and Taylor, 2004, fig. 3) showed that it comprises a succession of shallow water carbonates, including microbial reefs.Their abundance data for reef, inter-reef grainstone, and subtidal tempestite facies (Taylor et al., 1999, fig. 6;Loch and Taylor, 2004, table 1) showed that Deckera is, as in other regions, a minor component of the trilobite fauna.Deckera completa enters the succession at the base of the Cliffia latagenae Subzone of the Elvinia Zone as defined by Loch and Taylor (1995, fig. 8), and extends to the top of this unit, which is defined by the base of the overlying Irvingella 'major' Zone.The occurrence of species of Kindbladia and Plataspella in the lower Cliffia latagenae Subzone (Loch and Taylor, 1995, fig. 8;2004, fig.2), indicates that the basal part of this unit is correlative with Stitt's (1977) lower informal division of the Elvinia Zone.

Materials and methods
Specimens were coated with a sublimate of ammonium chloride prior to photography.Depth of field was maximized by rendering digital images from stacks of images focused at 100 μm intervals using Helicon Focus 4.0 for the Macintosh (http:// www.heliconsoft.com).Proportions expressed as percentages in descriptions and diagnoses are means, with the pair of numbers following indicating the range of values; unless indicated otherwise, data were derived from figured specimens.All measurements were made on digital images to the nearest tenth of a millimeter using the Measure Tool of Adobe Photoshop™.
Repositories and institutional abbreviations.-Illustratedspecimens are housed at the Geological Survey of Canada, Ottawa (GSC); the Oklahoma Museum of Natural History, University of Oklahoma, Norman (OU); and the Peabody Museum, Yale University, New Haven, Connecticut (YPM).

Systematic paleontology
Family Dokimocephalidae Kobayashi, 1935 Genus Deckera Frederickson, 1949 Expanding the diagnosis of Deckera is in our view preferable to establishing a new genus for the Paibian species, as such a genus would likely be paraphyletic.Our hypothesis of relationships can be evaluated by a broad phylogenetic analysis of family Dokimocephalidae.This would need to expand an initial revision and analysis of Dokimocephalus and closely related genera (Westrop et al., 2010) to include not only Deckera, but also such genera as Kindbladia, Dellea, and Pseudosaratogia.This will be a substantial undertaking and is well beyond the scope of this paper.Pygidial margin curved downward medially in posterior view.Small granules present throughout the pleural field; single large granule on posterior pleural bands.
The cranidium of Deckera completa (Fig. 5) from the Ore Hill Member of the Gatesburg Formation has more steeply inclined fixed cheeks (compare Fig. 5.3, 5.4, 5.9 with Fig. 3.2, 3.7, 3.9).The palpebral lobe of Deckera aldenensis is equal to only approximately one-fifth (21%) of glabellar length, whereas the palpebral lobe of Deckera completa is longer (exsag.)and equal to slightly more than one-third (36%) of glabellar length (e.g., Fig. 5.1, 5.10).The well-defined palpebral furrow of Deckera completa differs from the more gently impressed furrow of Deckera aldenensis, although preservation as internal molds (Fig. 5.1, 5.5, 5.10) could have accentuated the greater incision in the former.Deckera aldenensis has coarser granules on the fixigenae that are more abundant than those of Deckera completa, and the crest of the glabella also carries more coarse granules (compare Fig. 3.6, 3.7 with Fig. 5.9, 5.10); coarse granules are also present on the posterior pleural bands of the pygidium of Deckera aldenensis (Fig. 4.7, 4.8).The pygidium also differs from Deckera completa (Fig. 4.4-4.6) in having a narrower pleural field, and the pleural and interpleural furrows start curving backward relatively closer to the axis.Welch and Westrop-Deckera Frederickson, 1949 field flexing downward to upturned border.Border defined largely by absence of pleural and interpleural furrow; narrowing posteriorly.Posterior margin curving downward medially in posterior view.Fine granules present on axis, pleural bands, and border.Two anterior axial rings with pair of poorly defined larger granules.
Remarks.-Stitt (1971, pl. 1, fig. 16) assigned an incomplete cranidium from the Honey Creek Formation at Royer Ranch, Murray County, Oklahoma, to Deckera completa, but this specimen is too poorly preserved to be identified with any confidence.As recognized by Kurtz (1975Kurtz ( , p. 1026)), it is unusual in displaying a transverse posterior margin.A cranidium (Fig. 6.6-6.8)from the Honey Creek Formation at Dotson Ranch (5.6 km northwest of the Royer Ranch section), Murray County, is more informative, and is assigned questionably to Deckera completa.It is closely comparable to the type material of Deckera completa (Fig. 5).The relative proportions and slope of the anterior border and preglabellar field are identical, as are the size and position of the palpebral lobe, expression and orientation of the palpebral ridge, and the width (tr.) of the palpebral area of the fixigena (compare Fig. 5.1,5.2,5.5 with Fig. 6.6,6.8).The fixigenae of cranidia from Pennsylvania appear to be more steeply upsloping (compare Fig. 5.3,5.4,5.9 with Fig. 6.7).The sculpture of fine granules with scattered coarse granules on the fixigenae and crest of the glabella is shared between cranidia from Pennsylvania and the specimen from Oklahoma, but the coarser granules of the latter are more conspicuous, particularly on the anterior border.However, this difference is difficult to evaluate because expression of coarse granules on the border can vary between sclerites from a single collection in other species (e.g.,compare Fig. 7.1,7.3 with Fig. 7.10,7.11).
Deckera cf.D. aldenensis Frederickson, 1949 Figure 7 cf Remarks.-Cranidia from Nevada and Utah are related to the type species, Deckera aldenensis (Fig. 3), in sharing a short anterior border, a conical, anteriorly rounded glabella, and coarse granulose sculpture over most of the cranidium.They differ from Deckera aldenensis in that the palpebral lobes are centered farther forward, opposite S1 (e.g., Fig. 7.1), rather than L1 (e.g., Fig. 3.6).Additionally, the preglabellar field of Deckera cf.D. aldenensis occupies 57% (52-62%) of the frontal area length, whereas the preglabellar field of Deckera aldenensis is 44% (40-46%) of the frontal area length.The posterolateral projection of Deckera cf.D. aldenensis is deflected more strongly backward than in Deckera aldenensis (compare Fig. 3.6 and Fig. 7.10).The significance of these differences cannot be evaluated with the small number of sclerites available for study, therefore, the cranidia from Nevada and Utah are placed in open nomenclature.An associated free cheek (Fig. 7.7, 7.8) is assigned to Deckera cf.D. aldenensis because, although partly broken, it has a tall librigenal field that rises steeply from the border furrow.The long, slender genal spine is deflected downward in lateral view, producing a distinct curve in the lateral margin.Well defined anteriorly, the lateral border furrow becomes shallower posteriorly, and does not join the posterior border.The lateral border is of nearly equal thickness until it reaches the base of the genal spine where it thickens; the posterior border narrows slightly toward the genal spine.The borders and genal spine have fine granules; indistinct larger granules are present on the upper part of the librigenal field.
Description Remarks.-Palmer (1965, p. 92, pl. 3, fig. 18) described a single cranidium from the Dunderbergia Zone at Bastian Peak, Nevada, that he compared to Deckera.He recognized that all previously described species of Deckera had elevated palpebral lobes located far back on the cranidia at the crests of tall, strongly upsloping fixed cheeks, whereas his specimen   Deckera n. sp. 2 differs from Deckera n. sp. 3 in having a much longer preglabellar field, and fixed cheeks that are upsloping, rather than strongly inflated and flexing gently downward near the palpebral lobe (compare Fig. 9.1,9.2 with Fig. 9.5,9.6).To some extent, the anatomy of Deckera n. sp. 1 (Fig. 9.9-9.11)bridges the gap in morphology between these species, in that it has a short but clearly defined preglabellar field and gently inflated, nearly flat fixed cheeks.The upsloping cheeks and longer preglabellar field of Deckera n. sp. 2 are, in turn, gradational with more derived species, e.g., Deckera aldenensis (compare Fig. 9.2 with Fig. 3.7, 3.9).This apparent gradation is, in our view, a strong argument for including all three Paibian species in Deckera.Deckera sp.indet. 1 Figure 6.1-6.5 Occurrence.-Sneakover Limestone Member, Orr Formation, Orr Ridge, northern House Range (ORR 59.4).
Remarks.-An incomplete cranidium and pygidium from ORR 59.4 resemble Deckera completa from Pennsylvania 5).In particular, the cranidia share a long anterior border, which separates them from Deckera aldenensis (Fig. 3).However, the cranidium of Deckera sp.indet. 1 has well-incised glabellar furrows that distinguish it from both Deckera completa (e.g., A single cranidium from the Wind River Mountains of Wyoming was described by Lochman and Hu (1960) as cf.Deckera completa.Lochman and Hu (1960) stated that the Wyoming specimen has a preglabellar field to anterior border ratio of 1:1; the ratio seen in the Orr Ridge specimen is slightly < 2:3.Additionally, it appears that the glabellar furrows of the Wyoming specimen are not as deep.
Welch and Westrop-Deckera Frederickson, 1949  Remarks.-Kurtz (1975) identified cranidia from the Davis Formation of Missouri as Deckera cf.D. aldenensis, but they are treated as an indeterminate species here, albeit one that is probably new.Like Deckera aldenensis (Fig. 3), the only specimen that Kurtz (1975) figured (Fig. 4.1-4.3)has upsloping fixed cheeks, and the proportions of the anterior border and preglabellar field are similar.However, the anterior border furrow of this specimen is nearly transverse and, as noted by Kurtz (1975), the anterior border tapers abaxially to produce roughly triangular or nasute outline.In contrast, the anterior border and border furrow of Deckera aldenenis are distinctly curved.In addition, the cranidium from Missouri has a distinct anterior arch (Fig. 4.2) that is absent in Deckera aldenensis (Fig. 3.7, 3.9) The palpebral furrow is preserved on the left side of the cranidium and terminates opposite S2 (Fig. 4.1).This indicates that the palpebral lobe is longer (exsag.)than in Deckera aldenensis.The palpebral lobe of the Missouri specimen is similar in size and position to Deckera cf.D. completa from Oklahoma (Fig. 8.1, 8.5), but the latter has a relatively shorter preglabellar field, a curved anterior border and border furrow, and lacks an anterior arch (Fig. 8.2, 8.3).
Newfoundland.-Twocranidia of what is among the older species of Deckera, Deckera new species 2, are from a boulder (HC 166) in a debris flow conglomerate near the top of the Downes Point Member of the Shallow Bay Formation

Figure 1 .
Figure 1.Maps showing localities that yielded new material illustrated in this paper: (1) section ORR, measured on the ridge on the southeastern side of Big Horse Canyon, Orr Ridge, northern House Range, western Utah; (2) section CHC-2, measured on the southwestern side of Barton Canyon, Cherry Creek Range, eastern Nevada; (3) Dotson Ranch (DR) section, measured in northern Murray County, southern Oklahoma; (4) section KR2, measured on the western slopes of Ring Top Mountain, southern Oklahoma; (5) Hickey Cove (HC), to the east of Broom Point, Cow Head region, western Newfoundland.
15 https://doi.org/10.1017/jpa.2024.15Published online by Cambridge University Press Pterocephalia sp.indet.The collection was less than a meter below the base of the Sunwaptan Stage, as defined by collection ORR 60.3-60.4,which yielded Bartonaspis palmeri Westrop and Adrain, 2007, Bartonaspis wilsoni Westrop and Adrain, 2007, Kormagnostella advena Westrop and Adrain, 2013, as well as species of Irvingella Ulrich and Resser in Frederickson (1949)strongly flexed in posterior view.Long, multisegmented axis with at least five axial rings in front of terminal piece.Remarks.-Theoriginaldiagnosis of Deckera byFrederickson (1949), based on species from Jiangshanian strata, included strongly upsloping fixed cheeks and elevated palpebral lobes as important characters.The discovery of older (Paibian) species in the Dunderberg Formation of Nevada (Deckera n. sp. 1 herein) and the Shallow Bay Formation of Newfoundland (Deckera n. sp. 2 and Deckera n. sp. 3 herein) provides information on the anatomy of what we interpret as basal members of the genus that have some, but not all, of the characters of Jiangshanian species, e.g., Deckera aldenensis and Deckera completa.As discussed below, Deckera n. sp 1 and Deckera n. sp. 3 have gently inflated fixed cheeks that are nearly flat or even slightly down-sloping near the palpebral lobe.However, Deckera n. sp. 2 is closer to Deckera aldenensis, and has fixed cheeks that slope upward to the level of the crest of the glabella.In other respects, the Paibian species are quite similar and seem to grade toward the more derived set Frederickson, 1949eraaldenensisFrederickson,1949from the Honey Creek Formation, Arbuckle and Wichita mountains, Oklahoma (by original designation).Emended diagnosis.-Dokimocephalidaewith subrectangular cranidium with width (tr.) noticeably greater than length (sag.);broad (tr.)fixigenae.Consequently, anterior border forms wide rim.Glabella convex, tapered, and subrounded anteriorly; relatively long, occupying at least 70% of cranidial length.In all but some basal species, lateral glabellar furrows weak and can be expressed mostly as smooth regions lacking sculpture.Preglabellar field short.Palpebral area of fixed cheek steeply upsloping abaxially, with top near level of crest of glabella, but some basal species have gently inflated, nearly flat palpebral areas. of Jiangshanian species (see remarks on Deckera n. sp. 3, below).We modify the diagnosis here to accommodate species with gently inflated fixed cheeks and, consequently, palpebral lobes that are not elevated.The Paibian species also have more firmly incised lateral glabellar furrows.Cranidial characters emphasized in the revised diagnosis include a broad cranidium with wide palpebral areas of the fixigenae and, consequently, a wide (tr.) anterior border.Where known, the pygidium has a distinctive flexure of the margin in posterior view.
Deckera completa; Stitt, p. 18, pl. 1, fig.16 (= Deckera sp.indet.).Pygidial length ∼53% of maxiumum pygidial width.Axis convex, occupying ∼90% of pygidial length; width at first axial ring equal to ∼30% of maximum pygidial width.Six transverse axial rings; short terminal piece.Axial ring furrows firmly impressed.Pleural furrows well incised; interpleural furrows more finely etched.Pleural bands roughly equal in length (exsag.),nearly straight near axial furrow but curving strongly backward abaxially.Pleural on internal mold (Fig.5.1).Palpebral area sloping steeply upward at ∼45°, rising above crest of glabella.Palpebral lobe equal to more than one-third (36%) of glabella and located opposite L1 glabellar lobe, with posterior tip extending back to level of SO.Sculpture of fine granules with scattered coarser granules on glabella except for lateral furrows.Sparsely distributed larger granules on fixed cheeks, better expressed on internal mold; anterior border carrying only very fine granules.
Occurrence.-Barton Canyon Limestone Member, Windfall Formation, Barton Canyon, Cherry Creek Range (CHC-2 203.1) and the Corset Spring Shale Member, Orr Formation, Orr Ridge, northern House Range(ORR 7.5).An association with Irvingella angustilimbata in the latter collection indicates that the range Deckera cf.D. aldenensis extends to a point near the bases of the Elvinia Zone and Jiangshanian Stage.
.-Cranidum subrectangular in outline; width across palpebral lobes approximately twice cranidial length (excluding LO).Axial and preglabellar furrows well defined.Glabella convex, tapered, bluntly rounded anteriorly.Glabella occupying ∼80% of cranidial length.SO as shallow groove; LO incompletely preserved but curving backward.Oblique S1 and S2 glabellar furrows present, deepest abaxially.S1 extending farther inward than S2, curving toward SO.Very faint S3 expressed as slight indentation of glabellar margin.Palpebral area of fixed cheeks nearly flat, lying well below crest of glabella; width ∼70% of glabellar width at anterior tip of L2.Palpebral lobe semicircular in outline, upturned, situated opposite L2; length ∼40% of glabellar length.Palpebral furrow as narrow, deeply etched groove.Palpebral ridge extending obliquely forward, reaching axial furrow opposite S3.Frontal area short, ∼22% of cranidial length, 28% of glabellar length.Weakly convex, gently sloping preglabellar field occupying approximately one-third of frontal area length.Border furrow distinct, nearly transverse, bending toward glabella medially.Anterior border convex, widest (sag.)medially, tapering abaxially, nearly transverse.Anterior branches of facial suture directed slightly inward anteriorly.Posterior border flexed downward; posterolateral projection not preserved.Fixed cheeks evenly coated with small granules and scattered larger granules.Smaller granules present on glabella, except for furrows.Granules on anterior border more prominent than those on fixed cheeks and glabella.
length equal to ∼40% of glabellar length.The oblique palpebral ridge is conspicuous and reaches the axial furrow opposite S3.The external surface of the cranidium is granulose.The cranidia from the Dunderbergia Zone are interpreted as a basal species of Deckera, which possesses some, but not all of the characters of the genus.The diagnosis of the genus is revised above.Remarks.-AmongPaibianspecies,Deckeran.sp. 2 is most like younger members of the genus, e.g., Deckera aldenensis and Deckera completa.In particular, it possesses upsloping palpebral areas of the fixed cheeks and, although the slope is noticeably lower than in the latter two species, they do rise to the level of the crest of the glabella (e.g., compare Fig.9.2 with Figs.3.7,5.3).As a result, the palpebral lobe is elevated, although less so than in Deckera aldenensis and Deckera completa.The proportions of the cranidium of Deckera n. sp. 2 are similar to those of Deckera n. sp. 1 (Fig.9.9-9.11), with width (tr.) across the palpebral areas equal to at least 1.45 times cranidial length.However, Deckera n. sp. 1 has weakly inflated, nearly flat fixed cheeks.In other respects, Deckera n. sp. 1 and Deckera n. sp. 2 are similar, sharing bluntly rounded glabellae and incised lateral glabellar furrows.The preglabellar field is longer than in Deckera n. sp. 1, equal to ∼60% of frontal area length; frontal area occupies approximately one-quarter of cranidial length.In these respects, Deckera n. sp. 2 is more like Deckera aldenensis (e.g., Fig.3.6), and the relatively short anterior cranidial border is also comparable, although it is more transverse.The sculpture of Deckera n. sp. 2, which comprises closely spaced large granules and scattered fine tubercles, is unique.furrow; the oblique palpebral ridge is well defined.The preglabellar field is barely expressed.