Supplementary table 1. Taxonomy, classification and biostratigraphic data of Cambrian polymerid trilobites capable of complete enrolment. Modified and expanded from Esteve et al. (2011). Asterisk indicates hypothetical reconstruction of complete enrolment based on observable functional morphology. Chronostratigraphic data based on Babcock and Peng (2007) and International Chronostratigraphic Chart 2012. Global units highlighted in bold; Laurentian units highlighted in italics.
Taxon / Higher classification / Age / Reference
Bynumina lirae / Ptychopariida / Kingstoniidae / upper Cambrian / Stitt 1983; figs 3a-h
Cliffia lataegenae / Uncertain / upper Cambrian / Stitt 1983; figs 2h-k
Cliffia wilsoni / Uncertain / upper Cambrian / Stitt 1983; figs 2l-u
Drabia acroccipita / Uncertain / upper Cambrian / Stitt 1983; fig. 2v
Elyaspis missouriensis / Uncertain / upper Cambrian / Stitt 1983; figs 3i-m
Sulcocephalus candidus / Ptychopariida / Elviniidae / upper Cambrian / Stitt 1983; figs 2a-f
Stenopilus pronus / Asaphida / Plethopeltidae / upper Cambrian
(upper Sunwaptan) / Whittington 2005;
fig. 2
Leiocoryphe gemma* / Asaphida / Plethopeltidae / upper Cambrian / Whittington 2003;
fig. 4
Plethopeltis armata / Asaphida / Plethopeltidae / upper Cambrian / Whittington 2003;
figs 1.3, 1.5, 1.6
Diceratocephalus cornutus / Ptychopariida / Diceratocephalidae / late middle Cambrian
(Marjuman) / Park and Choi 2010;
figs 7O, P
Bolaspidella housensis / Ptychopariida / Bolaspidae / middle Cambrian
(Marjuman) / Robison 1964;
plate 89, fig. 8
Solenopleura / Ptychopariida / Solenopleuridae / middle Cambrian (Drumian) / Westergård 1936
Eccaparadoxides pradoanus / Redlichiida / Redlichiina / Paradoxididae / middle Cambrian
(Drumian) / Esteve et al. 2011;
fig. 1f
Eccaparadoxides cf. brachyrachis + / Redlichiida / Redlichiina / Paradoxididae / middle Cambrian
(Drumian) / Becq-giraudon and Baillat 2005; fig. 1
Paradoxides gracilis / Redlichiida / Redlichiina / Bathynotidae / middle Cambrian
(Drumian) / Pompejick 1896; see alsoŠnajdr 1957
Schopfaspis? graciai / Ptychopariida / Alokistocaridae / middle Cambrian
(Drumian) / Esteve et al. 2012;
fig. 3k
Pardailhania cf. hispida / Ptychopariida / Solenopleuridae / middle Cambrian
(Drumian) / Esteve et al. 2010;
fig. 7
Solenopleuropsis sp. / Ptychopariida / Solenopleuridae / middle Cambrian
(Drumian) / Esteve et al. 2010;
figs 3, 4, 8, 10
Solenopleuropsis thorali / Ptychopariida / Solenopleuridae / middle Cambrian
(Drumian) / Esteve et al. 2010;
fig. 9a
Conocoryphe heberti / Ptychopariida / Conocoryphidae / middle Cambrian
(Drumian) / Esteve et al. 2011;
fig. 1e
Agraulos longicephalus / Ptychopariida / Agraulidae / middle Cambrian
(Drumian) / Esteve 2013;
fig. 5
Ctenocephalus antiquus / Ptychopariida / Conocoryphidae / middle Cambrian
(Drumian) / Esteve 2013;
Figs 3a, b
Hydrocephalus carens / Redlichiida / Redlichiina / Paradoxididae / middle Cambrian
(Stage 5 – Drumian) / Barrande 1852; see alsoŠnajdr 1957
Conocoryphe / Ptychopariida / Conocoryphidae / middle Cambrian
(Stage 5 – Drumian) / Barrande 1852
Sao / Ptychopariida / Solenopleuridae / middle Cambrian
(Stage 5 – Drumian) / Barrande 1852
Bathynotus holopygus* / Redlichiida / Redlichiina / Bathynotidae / middle Cambrian
(Stage 5) / Shergold and Whittington 2000; fig. 3
Parasolenopleura gregaria / Ptychopariida / Solenopleuridae / middle Cambrian
(Stage 5) / Fletcher 2005;
plate 2, fig. 16
Supplementary table 1. Continued.
Taxon / Higher classification / Age / Reference
Ellipshocephalus hoffi* / Ptychopariida / Ellipsocephalidae / late lower Cambrian
(Stage 4) / Geyer 1990;
plate 14, fig. 1
Kymataspis arenosa* / Ptychopariida / Ellipsocephalidae / late lower Cambrian
(Stage 4) / Geyer 1990;
plate 37, fig. 1
Termiella latifrons* / Ptychopariida / Ellipsocephalidae / late lower Cambrian
(Stage 4) / Geyer 1990;
plate 56, fig. 11
Strenuaeva inflata / Ptychopariida / Ellipsocephalidae / lower Cambrian
(Stage 4) / Cederström et al. 2011; fig. 12
Crassifimbra walcotti / Ptychopariida / Agraulidae / lower Cambrian
(upper Dyeran / Stage 4) / Palmer 1958;
plate 26, figs 13-15
Zacanthopsis palmeri / Corynexochida / Zacanthoididae / lower Cambrian
(upper Dyeran / Stage 4) / Hopkins and Webster 2009; figs 11.23-28
Redlichia forresti* / Redlichiida / Redlichiina / Redlichiidae / lower Cambrian
(Stage 4) / McNamara 1986;
figs 3-5
Ellipsocephalus sanctacrucensis / Ptychopariida / Ellipsocephalidae / lower Cambrian
(Dyeran / Stage 4) / Orlowski 1985;
p. 238
Nephrolenellus geniculatus / Redlichiida / Olenellina / Olenellidae / lower Cambrian
(upper Dyeran / Stage 4) / Webster 2007;
fig. 14.6
Olenellus chiefensis / Redlichiida / Olenellina / Olenellidae / lower Cambrian
(upper Dyeran / Stage 4) / Palmer 1998;
fig. 11.3
Olenellus gilberti / Redlichiida / Olenellina / Olenellidae / lower Cambrian
(upper Dyeran / Stage 4) / Palmer 1998;
fig. 9.1
Mummaspis ?muralensis / Redlichiida / Olenellina / Olenellidae / lower Cambrian
(lower Dyeran / Stage 4) / this study;
fig. 1a
Mummaspis occidens / Redlichiida / Olenellina / Olenellidae / lower Cambrian
(lower Dyeran / Stage 4) / this study;
fig. 1b
Mummaspis truncatooculatus* / Redlichiida / Olenellina / Olenellidae / lower Cambrian
(lower Dyeran / Stage 4) / this study;
figs 1c,d
Fallotaspis sp.* / Redlichiida / Olenellina / Fallotaspididae / lower Cambrian (Montezuman) / Bergström 1973;
fig. 8b
Schmidtiellus sp.* / Redlichiida / Olenellina / Olenellidae / lower Cambrian / Bergström 1973;
p. 16
+ Eccaparadoxides cf. brachyrachis (= Eccaparadoxides mediterraneus see Dies-Alvarez et al. 2010; = Eccaparadoxides pradoanus in Esteve in press).

Supplementary figure 1. Complete enrolment (a, d-f) and ventral flexure (b, c) in Cambrian redlichiine (a, b) and olenelline (c-f) trilobites. (a)MPZ 2012/750, complete enrolment in the middle Cambrian (Drumian) paradoxidid Eccaparadoxides pradoanus in ventral view (see also Esteve et al. 2011, 2013); (b)MPZ 2012/747, ventral flexure in Eccaparadoxides pradoanus (see also Esteve et al. 2011, 2013) showing lateral overlap of the trunk pleurae (arrowheads); (c) FMNH PE57944, the early Cambrian (upper Dyeran) olenellid Nephrolenellus geniculatus in dorsal view (see also Webster 2007); (d) DMNH 16701a, the early Cambrian (upper Dyeran) olenellid Olenellus gilberti part in ventral view (see also Palmer 1998); (e) DMNH 16080 part, the early Cambrian (upper Dyeran) olenellid Olenellus chiefensis in ventral view (see also Palmer 1998); (e) DMNH 16080 counterpart. Scale bars = 5 mm. Abbreviations: ahr, articulating half ring; tl, terrace lines. Institutional abbreviations: MPZ, Museum of Palaeontology of Zaragoza (Zaragoza, Spain); DMNH, Denver Museum of Nature and Science (Denver, USA); FMNH, Field Museum Chicago (Chicago, USA). Photograph credit: (d-f), J. W. Hagadorn (DMNH); (c), M. Webster (University of Chicago).

References

Babcock LE, Peng S. 2007. Cambrian chronostratigraphy: current state and future plans. Palaeogeography Palaeoclimatology Palaeoecology254, 62-66.

Barrande J. 1852. Sytéme Silurien du Centre de la Bohême, 1ere Partie, Crustacés, Trilobites. 1-935. Praha. Paris.

Becq-Giraudon JF, Baillat A. 2005. Eccaparadoxides (Trilobita) pouvaint s’enrouler. Un exemple rare du Cambrian moyen de Coulouma, Montagne Noire (Hërault, France): Bulletin de la Société Sciences Naturelle Ouest de la France 27, 153-156.

Bergström J. 1973. Organization, life and systematics of trilobites. Fossils & Strata2, 1-69.

Cederström P, Ahlberg P, Nilsson CH, Ahlgren J, Eriksson ME. 2011. Moulting, ontogeny and sexual dimorphism in the Cambrian pthychopariid trilobite Strenuaeva inflata from the northern Swedish Caledonides. Palaeontology 54, 685-703. (doi: 10.1111/j.1475-4983.2010.01021.x).

Dies-Álvarez ME, Rushton AW, Gozalo R, Pillola GL, Liñán E, Ahlberg P. 2010. Paradoxides brachyrachis Linnarsson, 1883 versus Paradoxides mediterraneus Pompeckj, 1901: a problematic determination. GFF 132, 95-104. (doi: 10.1080/11035897.2010.481363).

Esteve J. 2013. Revisión del enrollamineto en los trilobites del Cámbrico español y su implicación en la evolución de los trilobites. Estudios Geológicos (online), accepted manuscript. (doi: 10.3989/egeol.41215.259).

Esteve, J. in press. Intraspecific variability in paradoxidid trilobites from the Purujosa trilobite assemblage (middle Cambrian, northeast Spain). Acta Paleontologica Polonica. early view online (doi: 10.4202/app.2012.0006).

Esteve J, Zamora S, Gozalo R. Liñán E. 2010. Sphaeroidal enrolment in middle Cambrian solenopleuropsine trilobites. Lethaia43, 478-493. (doi: 10.1111/j.1502-3931.2009.00205.x)

Esteve J, Hughes NC, Zamora S. 2011. Purujosa trilobite assemblage and the evolution of trilobite enrollment. Geology39, 575-578. (doi: 10.1130/G31985.1).

Esteve J, Sundberg FA, Zamora S, Gozalo R. 2012. A new Alokistocaridae Resser, 1939 (Trilobita) from the middle Cambrian of Spain. Geobios 45, 275-283. (doi: 10.1016/j.geobios.2011.10.003).

Esteve J, Hughes NC, Zamora S. 2013. Thoracic structure and enrolment style in middle Cambrian Eccaparadoxides pradoanus presages caudalization of the derived trilobite trunk. Palaeontology56, 589-601. (doi: 10.1111/pala.12004).

Fletcher TP. 2005. Holaspid variation in the solenopleurid trilobite Parasolenopleura gregaria (Billings, 1865) from the Cambrian of Newfoundland. Palaeontology 48, 1075-1089. (doi: 10.1111/j.1475-4983.2005.00494.x).

Geyer, G. 1990. Die marokkanischen Ellipsocephalidae (Trilobita: Redlichiida). Beringeria 3, 1-363.

Hopkins MJ, Webster M. 2009. Ontogeny and geographic variation of a new species of the corynexochine trilobite Zacanthopsis (Dyeran, Cambrian). Journal of Paleontology 83, 524-547.

McNamara KJ. 1986. Techniques of exuviation in Australian species of the Cambrian trilobite Redlichia. Alcheringa10, 403-412.

Orlowski S. 1985. Lower Cambrian and its trilobites in the Holy Cross Mts. Acta Geologica Polonica 35, 231-250.

Palmer AR. 1958. Morphology and ontogeny of a lower Cambrian ptychoparioid trilobite from Nevada. Journal of Paleontology 32, 154-170.

Palmer AR. 1998. Terminal early Cambrian extinction of the Olenellina: documentation from the Pioche Formation, Nevada. Journal of Paleontology 72, 650-672.

Park TY, Choi DK. 2010. Two middle Cambrian diceratocephalid trilobites, Cyclolorenzella convexa and Diceratocephalus cornutus, from Korea: development and functional morphology. Lethaia43, 73-87. (doi: 10.1111/j.1502-3931.2009.00168.x).

Pompejick JF. 1896. Die Fauna des Cambrium von Tejrovic und Skrej in Böhem: J. geol. Reichsanstatl Vienne 45: 495-614.

Robison RA. 1964. Late middle Cambrian faunas from western Utah. Journal of Paleontology 38, 510-566.

Shergold JH, Whittington HB. 2000. The Cambrian triloibte Bathynotus (?Redlichioidea) in the Northern Territory, Australia. Alcheringa24, 1-10.

ŠnajdrM. 1957. O nových trilobitech zčeského kambria. Vӗstnik Ústředniho ústavu geologického 32, 235–244.

Stitt JH. 1983. Enrolled late Cambrian trilobites from the Davis Formation, southeast Missouri. Journal of Paleontology 57, 93-105.

Webster M. 2007. Ontogeny and evolution of the early Cambrian trilobite genus Nephrolenellus (Olenelloidea). Journal of Paleontology 81, 1168-1193.

Westergård, AH. 1936. Paradoxides aeladicus beds of Öland with he account of diamond boring through the Cambrian at Mossberga. Sveriges Geologiska Undersökning Ser. C. 394, 1-66.

Whittington HB. 2003. The Upper Cambrian trilobites Plethopeltis and Leiocoryphe; morphology, paedomorphism, classification. Journal of Paleontology 77, 698-705.

Whittington HB. 2005. The Upper Cambrian trilobite Stenopilus: morphology, mode of life. Journal of Paleontology 79, 259-266.

1