1

BRACHIOPODS AND SMALL SHELLY FOSSILS FROM THE BASAL

KINZERS FORMATION (CAMBRIAN SERIES 2, STAGE 4) OF

PENNSYLVANIA

CHRISTIAN B. SKOVSTED AND JOHN S. PEEL

Department of Earth Sciences (Palaeobiology), Uppsala University,

Villavägen 16, SE-752 36 Uppsala, Sweden <christian.skovsted@geo.uu.se>

<john.peel@pal.uu.se>

INTRODUCTION

The first American specimens of Yochelcionella, a problematic Cambrian

mollusk genus characterized by a prominent snorkel, were described from

Thomasville, Pennsylvania by Runnegar and Pojeta (1980). Later

investigations of lower Cambrian faunas from other areas of North America

(Peel 1987; Landing and Bartowski 1996; Landing et al 2002; Skovsted 2004,

2006a; Atkins and Peel 2004, 2008) have since shown that Yochelcionella is

a member of a diverse and widespread fauna of Small Shelly Fossils

occurring along the eastern margin of Laurentia in the later part of the lower

Cambrian (Cambrian Series 2, stage 4 in the proposed subdivision of the

Cambrian, see Babcock et al. 2005). In this report we extend the distribution

of this fauna southwards along the Appalachians to Pennsylvania (Fig. 1), in

reporting an assemblage of 17 taxa of Small Shelly Fossils from Thomasville.

Most components of this assemblage have a considerable geographic range,

suggesting the presence of a continuous shelf community with few barriers to

the dispersal of animals along the eastern and northern margins of Laurentia

in the early Cambrian.

Cambrian strata of Laurentian aspect in eastern North America outcrop

in a more than 2000 km long belt from Alabama in the south through the

Appalachians to Quebec in the north (Palmer 1971). Small outcrops occur in

western Newfoundland and adjacent Labrador (Schuchert & Dunbar 1934;

Knight 1991), and in North-East Greenland (Skovsted 2006a), before

essentially continuous outcrop returns in the Franklinian Basin succession

that extends east-west across North Greenland and into the Canadian Arctic

Islands (Peel and Sønderholm 1991). Lower Cambrian faunas have been

recorded from these successions for about 150 years. Monographs by

Walcott (1886), Poulsen (1932), Resser and Howell (1938) and Lochman

(1956) are dominated by macrofossils, overwhelmingly trilobites, but in recent

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years paleontological enquiry has been directed towards Small Shelly Fossils

recovered by the digestion of carbonates in weak acids. The technique has

been widely employed by Russian palaeontologists (e.g. Rozanov et al. 1969)

and is now a standard approach to investigating the biostratigraphy of

Cambrian carbonate successions (e.g. Kerber 1986; Qian & Bengtson 1989;

Bengtson et al. 1990; Esakova & Zhegallo 1996; Gubanov et al. 2004).

The name Small Shelly Fossils is an embracive term that covers a

broad array of Cambrian fossils united by their small size (generally 1-2 mm

or less) and the method of extraction. The term encompasses the remains of

such diverse groups as mollusks, brachiopods and sponges in addition to a

host of more problematic fossils. In the Cambrian of eastern North America

description of Small Shelly Fossils was pioneered by Ed Landing (Albany) and

others working in Laurentian and Avalonian terranes (for references see

Landing and Bartowski 1996; Landing et al. 2002, 2008), but faunas have also

been described from the Laurentian successions in the Forteau Formation of

western Newfoundland (Peel 1987; Skovsted 2003a; Skovsted and Peel,

2007), the Bastion and Ella Island formations of North-East Greenland

(Skovsted 2003b, 2004, 2005, 2006a; Skovsted and Holmer 2003, 2005;

Skovsted and Peel 2001; Skovsted et al. 2004; Malinky and Skovsted 2004;

Peel and Skovsted 2005) as well as the Aftenstjernesø Formation of North

Greenland (Atkins and Peel 2004, 2008; Peel and Larsen 1984).

GEOLOGICAL SETTING

In eastern Pennsylvania Cambrian carbonates of the Vintage, Kinzers

and Ledger formations, overlying siliclastic sediments of the Antietam

Formation, record a basin to shelf sequence (Cambrian Series 2 and 3)

suggesting growth and west to east progradation of a carbonate shelf margin

(Reinhardt 1977; Skinner 2005; Fig. 1). The Vintage Formation (150-245 m

thick) consists of mottled or banded limestones and dolomites of basinal

aspect. The overlying Kinzers Formation (45-155 m) includes a lower pelitic

member (Emigsville Member), an overlying York Member of shelf edge

carbonates and massive breccias, followed by argillaceous to sandy

carbonates of the Longs Park and Greenmount members.

Samples described during this study were collected from the quarry at

the junction of Lincoln Highway (U.S Route 30) and Biesecker Road (39

55.3 N, 76 51.2 W) in Thomasville, York County, Pennsylvania (Fig. 1).

Long operated by Thomasville Stone and Lime Company, it is now owned by

Oldcastle Industrial Minerals. The main quarry complex is located in massive

limestones, mainly debris flows, of the Kinzers Formation but the crushed

stone quarry, to the south-west, lies within the underlying Vintage Formation

(Cloos 1968). Fossils were collected by J.S. Peel from the so-called water

pipe section, exposed in the west wall of the roadway between the two

quarries, about 50 m south of the down faulted phyllite of the Emigsville

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Member of the Kinzers Formation (Gohn 1976). About 10 m of fossiliferous,

dark, thin bedded, argillaceous limestone overlie a bed of white limestone

breccia described by Gohn (1976) as the uppermost unit of the Vintage

Formation. Yochelson (1970) referred the beds below the fossiliferous strata

to the “Thomasville” limestone. This informal unit, also used by Reinhardt

(1977), is an atypical development of the York Member of the Kinzers

Formation, characterized by 2 megabreccia units (Ganis & Hopkins 1990) and

is not part of the Vintage Formation, as Gohn (1976) had suggested.

Gohn (1976) referred the fossiliferous limestones to the Emigsville

Member, although Yochelson (1970, p. B7) followed Cloos (1968) and

referred this “atypical dark-gray limestone unit” to the Vintage Dolomite. Atkins

and Peel (2008), in describing Yochelcionella, referred to the unit as the

lowest Kinzers Formation; Skinner (2005) did not include the locality in his

description of the Emigsville Member lagerstätte.

FAUNAL COMPOSITION

The Small Shelly Fossil assemblage from Thomasville is moderately

diverse, with a total of 17 taxa (Table 1). It is dominated numerically and

taxonomically by organophosphatic brachiopod shells and internal molds of

mollusks, but hyoliths, tubular problematica, sponge spicules and echinoderm

ossicles are also present.

Most of the recovered fossils are either phosphatic by original

composition (brachiopods and Hyolithellus) or represented by phosphatic

internal molds (mollusks, Salterella). However, some hyoliths, chancelloriid

sclerites and some sponge spicules appear to have been secondarily

replaced, at least partly, by phosphate or silica, and echinoderms and

Dodecaactinella spicules are also represented by partly etched

monocrystaline calcitic plates.

Skinner (2005) described a number of Small Shelly Fossil taxa from the

shales of the Emigsville Member of the Kinzers Formation (e.g. Pelagiella,

Chancelloria, Alonnia, Tubulella, Salterella etc.) but their preservation is too

poor to allow meaningful comparison with the fauna from acid residues

described herein.

Mollusks.─ Mollusks are represented by internal molds of five species,

including Yochelcionella (three species described by Atkins and Peel 2008),

Planutenia flectata and Pelagiella sp. In addition to the previously known,

strongly coiled and laterally compressed Y. americana (Fig. 2.3-2.5),

Yochelcionella is represented by the relatively wide and upright forms Y.

chinensis (Fig. 2.1, 2.2) and Y. greenlandica (Fig. 2.6). These are also

present in the Aftenstjernesø Formation of North Greenland (Atkins & Peel

2008) and, with the exception of Y. greenlandica, in the Forteau Formation of

western Newfoundland (Skovsted and Peel 2007). Yochelcionella chinensis is

probably also present in North-East Greenland (Yochelcionella sp.; Skovsted

4

2004) and the Taconic Allochthon of New York State (Yochelcionella sp.;

Landing and Bartowski 1996).

A single, partly broken internal mold showing strong lateral compression

(Fig. 2.7) resembles Planutenia flectata from the Lower Cambrian of eastern

Germany (Elicki 1994) and western Newfoundland (Skovsted and Peel 2007).

In lateral view P. flectata is similar to Yochelcionella americana, but is more

strongly compressed and is further distinguished by the absence of co-

marginal ribs and snorkel.

Internal molds of asymmetrically coiled molluscs are similar to Pelagiella

primaeva, otherwise known from the Taconic Allochthons of New York State

and Quebec and from North Greenland (Fig. 2.8-2.11). The apices of the

molds are depressed below the margin of the aperture (in apertural view), and

differ in this respect from specimens referred to P. subangulata from Australia

and North-East Greenland (Parkhaev in Gravestock et al. 2001; Skovsted

2004) and Pelagiella sp. from western Newfoundland (Skovsted and Peel

2007). However, identification of internal molds of Pelagiella is problematic

(Parkhaev in Gravestock et al. 2001; Skovsted and Peel 2007), and these

specimens are left in open nomenclature.

Hyoliths.─ Hyoliths are represented by conchs of both orthothecids and

hyolithids. The orthothecid conchs are slowly expanding, gently curved and

exhibits a circular cross-section (Fig. 2.12-2.14) comparable with Conotheca

australiensis which is common in the Bastion Formation of North-East

Greenland (Malinky and Skovsted 2004). Hyolithid conchs with a triangular

cross section are generally less well preserved and are left in open

nomenclature (Fig. 2.15, 2.16).

Brachiopods.─ Organophosphatic brachiopods are represented by four

species, including Eothele tubulus, Eoobolus priscus, Hadrotreta sp. and

Micromitra sp.

The most common brachiopod shells in the assemblage are conical

ventral valves of Eothele tubulus with a relatively coarse ornament of pustules

and an oval pedicle foramen (Fig. 4). Eothele tubulus was originally described

from the Mackenzie Mountains of Canada (Voronova et al. 1987) but also

occurs in western Newfoundland (Skovsted and Peel 2007). Since the

species is poorly known, it is described in detail on the basis of the

Thomasville material to record important new information concerning shell

structure.

The second most common brachiopod in the Thomasville fauna is the

acrotretid Hadrotreta sp. (Fig. 2.18-2.21). All specimens are fragmentary and

most are partially exfoliated, precluding a definite specific identification. The

strongly developed apical process on the ventral valve interior suggests

affinity with H. primaeva from the Great Basin (Walcott 1902; M. Streng pers.

comm. 2009).

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Thomasville specimens of Eoobolus priscus are fragmentary (Fig. 2.22)

but appear to be identical to better preserved material described from North-

East Greenland (Poulsen 1932; Skovsted and Holmer 2005). This species is

widespread along the east Laurentian margin (North-East Greenland, western

Newfoundland, New York State) but is also found in Antarctica and South

Australia (Skovsted and Holmer 2005; Skovsted and Peel 2007). A few poorly

preserved but highly convex brachiopod specimens with a low median ridge

and a concave delthyrium with probable delthyrial ridges on the internal

surface are suggestive of the genus Micromitra (Fig. 2.17). This genus is

known from most Lower Cambrian areas in Laurentia but the poor

preservation of the specimens from Pennsylvania precludes any specific

assignment.

Other fossils.─ Other taxa are relatively rare in the Thomasville samples.

Cone-shaped internal molds and silicified conchs of Salterella mccullochi (Fig.

3.1-3-3) may also be common on outcrop. The conchs are simple, poorly

preserved cones but internal molds combine a regular cone with a tubular

extension at the apex witch represents the mould of the central canal. Similar

material is common in fossil assemblages from western Newfoundland (Peel

and Berg-Madsen 1988; Skovsted 2003; Skovsted and Peel 2007) and North-

East Greenland (Skovsted 2006a). Salterella mccullochi is a well known

macrofossil from most Lower Cambrian regions of Laurentia ( Fritz and

Yochelson 1988). A second species, S. conulata, has been reported from the

Thomasville area (Yochelson 1970), but the present acid isolated specimens

differ from S. conulata by the relatively low rate of expansion of the conch.

Salterella ascervulosa described by Resser and Howell (1938) and Skinner

(2005) from the Emigsville lagerstätte probably represents poorly preserved

specimens of S. mccullochi.

Chancelloriid sclerites are scarce and their generalised morphology

precludes meaningful taxonomic determination (Fig. 3.4-3.6). Sponges are

represented by fragmentary spicules of Dodecaactinella (Fig. 3.7, 3.8) and

unidentified hexactinellids (Fig. 3.9). In addition, the fauna includes short

sections of organophosphatic tubes attributable to Hyolithellus micans (Fig.

3.10, 3.11). At least some of the similar fossils reported as Selkirkia by Resser

and Howell (1938; see also Conway Morris 1977)) and Tubulella by Skinner

(2005) from the Emigsville Member may also represent Hyolithellus. Star-

shaped echinoderm ossicles are also preserved, both as phosphatic replicas

and as partly etched calcitic plates (Fig. 3.12-3.15).

THE LOWER CAMBRIAN FAUNA OF EAST LAURENTIA

The currently documented fauna from the basal Kinzers Formation of

Thomasville is very similar to faunas from other regions within eastern

Laurentia (Table 1), confirming the pattern of wide geographical distribution of

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many Small Shelly Fossils (Skovsted 2004, 2006a; Malinky and Skovsted

2004; Skovsted and Peel 2007). The extensive similarities of faunas from

North Greenland to Pennsylvania suggest that a more or less continuous shelf

existed in eastern Laurentia during the early Cambian and that no substantial

barriers obstructed the migration of the fauna along the shelf.

The Thomasville fauna occurs in storm beds in the basal Kinzers

Formation which were deposited in a distal shelf setting. Assemblages from

western Newfoundland (Skovsted and Peel 2007), from the Bastion Formation

of North-East Greenland (Skovsted 2006a) and the Aftenstjernesø Formation

of North Greenland (Atkins and Peel 2004, 2008) are found in closely

comparable settings, while faunas from New York State (Landing and

Bartowski 1996) and Quebec (Landing et al. 2002) are derived from proximal

turbidites in a continental slope setting. Thus, all known shelly fossils from the

Lower Cambrian of eastern Laurentia are allochthonous and were potentially

transported for considerable distances prior to deposition. The majority of the

material was probably derived from proximal, and presumably more shallow

water environments on the Cambrian shelf along the eastern coast of

Laurentia.

With the exception of brachiopods (Rowell 1977, 1980) comparable

Small Shelly Faunas from western Laurentia are very poorly known. Salterella

is widely distributed in western Laurentia (Fritz and Yochelson 1988), but

other non-trilobite components of the fauna have been documented only in a

few publications describing material from the northern Rocky Mountains in

Yukon and Canada (Voronova et al. 1987) and the southern Great Basin

(Skovsted 2006b; Skovsted and Holmer 2006). Although the brachiopods of

the Kinzers Formation show some affinity with faunas from western Laurentia

(e.g. Eothele tubulus and Hadrotreta sp.), no other components are known

from both regions.

SYSTEMATIC PALEONTOLOGY

Repository.─ All figured specimens are deposited in the paleontological

type collection of the Museum of Evolution, Uppsala University, Sweden

(acronym PMU). The acronym GSC stands for Geological Survey of Canada,

Ottawa.

Family Acrothelidae Schuchert, 1893

Genus Eothele Rowell, 1980

Eothele tubulus Ushatinskaya in Voronova et al. 1987

Figure 4.1-4.19

Eothele tubulus Ushatinskaya in Voronova et al. 1987, p.50, pl. 22, figs 1-6,

pl. 23, fig.3.

Eothele sp. Skovsted and Peel 2007, fig. 2C.

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Holotype. ─ GSC N 90245 (Voronova et al. 1987, pl. 22, fig. 1), from

sample N42, collected 10 m. below locality GSC 95527, Mackenzie

Mountains, Northwest Territories, Canada. The authors do not state from

which rock unit sample N42 was collected, but based on their stratigraphic

diagram it was derived from an unidentified unit above the upper boundary of

the Sekwi Formation, just below the upper boundary of the Bonnia-Olenellus

Zone.

Diagnosis. ─ Species of Eothele with elongate lenticular pedicle

foramen and reduced internal pedicle tube. It differs from E. spurri and E.

granulata by the smaller pedicle opening, its lenticular shape, the short

pedicle tube and the less pronounced anterior flexing of the ventral valve.

Material. ─Six figured (PMU x1-x6) and 24 additional ventral valves

from acid-resistant residues of limestone samples from the basal Kinzers

Formation, Thomasville, Pennsylvania, USA.

Description. ─: The ventral shell is strongly procline with a pointed

apex (Fig. 4). In lateral profile the anterior is concave and the posterior slightly

convex (Fig. 4.8). Although all available specimens are incomplete, the

posterior margin appear to be gently curved and the shell was probably

semicircular in outline (Fig. 4.1, 4.7, 4.9). The pedicle foramen is lenticular,

with the posterior end slightly more rounded than the apical termination (Fig.

4.2, 4.7, 4.11). The foramen is 250 to 300 µm long and is completely closed

posteriorly by a flat triangular plate (Fig. 4.10). The well preserved ventral

larval shell is transversely oval to almost circular in outline (Fig. 4.3). A high,

rounded, central tubercle is present above the deep, V-shaped pedicle notch

and two low tubercles are present anteriorly (Fig. 4.4). The larval shell has a

distinct pitted micro-ornament with the diameter of pits varying from 2 to 6 µm

(Fig. 4.5). The post larval shell is ornamented by distinct, rounded pustules,

sometimes arranged in uneven, roughly co-marginal bands (Fig. 4.6). The

diameter of pustules is 8 to 15 µm and generally increases anteriorly.

Concentric ornament is more clearly defined on the posterolateral shoulders

and pseudointerarea but the pustules are less well developed here (Fig. 4.2,

4.7, 4.9). The posteromedian triangular plate exhibits slightly uneven

concentric growth lines without pustules (Fig. 4.2, 4.10). The ventral interior is

not well preserved but the pedicle foramen has a narrow rim, slightly elevated

above the valve floor anteriorly (Fig. 4.12, 4.17). A V-shaped muscle field is

present anterior to the pedicle foramen (Fig. 4.12, 4.17) and a pair of possible

umbonal or transmedian muscle scars are present slightly lateral and

posterior to the pedicle foramen (Fig. 4.12).

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Shell structure. ─ The microstructure of the shells was observed on

broken shell edges. The shell is clearly stratified with distinct sets of columnar

laminae (Fig. 4.18). The laminae are typically 5 to 8 µm thick and are

separated by narrow slits (less than 1 µm wide; Fig. 4.16, 4.18). Two types of

columnar structures are present, with columnar elements being either

perpendicular to the lamniae or inclined by approximately 30 degrees. Some

laminae are dominated by vertical columns (Fig. 4.16, 4.18) and others by

inclined columns (Fig. 4.15, 4.17), while some layers exhibit both vertical and

inclined columns (Fig. 4.19). The columnar elements are composed of

massive microgranular phosphate and are typically 1 to 2 µm thick. No central

canals were observed in the columnar elements (Fig. 4.16) and interlaminar

surfaces exhibit no perforations (Fig. 4.19).

Discussion. ─ The collection of Eothele tubulus from the Kinzers

Formation is exclusively composed of ventral valves, presumably an effect of

sorting during transport prior to deposition. Pre-burial transport and abrasion

is also indicated by the incompleteness of the shells which always lack the

anterior margin, although the posterior margin may sometimes be preserved.

Eothele differ from Botsfordia and Karathele by the presence of a pedicle

foramen completely enclosed by the posterior valve margin and from

Acrothele and Orbithele by the high, conical profile of the ventral valve.

Eothele tubulus was originally described from upper lower Cambrian (as

conventionally defined in Laurentia by the presence of Olenellus) of the

Mackenzie Mountains in Northwest Territories, Canada by Voronova et al.

(1987). The holotype (Voronova et al. 1987, pl. 22, fig. 1) is a slightly

damaged ventral valve which is closely comparable to the new specimens in

terms of shell morphology as well as the position and shape of the pedicle

foramen. The incomplete state of all specimens of E. tubulus hampers specific

characterisation but the species can be differentiated from the type species,

E. spurri, and E. granulata by the size and shape of the pedicle foramen

which is small and oval, lenticular rather than subtriangular and by the lack of

a distinct tubular internal extension of the pedicle foramen (Walcott 1908;

Roberts and Jell 1990). The anterior flexing of the valve also appears to be

less pronounced and the apex is less strongly elevated above the rest of the

ventral valve.

Specimens referred to Eothele sp. by Skovsted and Peel (2007) from the

Forteau Formation of western Newfoundland are identical to the material from

Pennsylvania and are here reinterpreted as E. tubulus. Specimens referred to

Eothele cf. spurri from the middle Cambrian Sidi-Saïd-Maâchou

volcanosedimentary complex of Morocco (Alvaro et al. 2008) have a similar

lenticular pedicle foramen, but their poor preservation precludes definite

taxonomic evaluation.

One unusual specimen is strongly deformed by a circumferential

constriction of the ventral valve resulting in an elongated, almost tubular

9

shape (Fig. 4.13). The specimen was probably affected by deformation in life

and seems to have responded to the damage by secretion of thick columnar

shell layers at an angle to shell layers in the primary shell (Fig. 4.14). The

shell preserves no external markings that may be related to physical damage

(except the unusual shape) and the nature of the process leading to the

preserved morphology is difficult to deduce.

The shell structure of Eothele tubulus was briefly described as columnar

by Ushatinskaya (in Voronova et al. 1987, p. 50), but the material from

Thomasville allow a more detailed investigation. Based on the lack of central

canals in the narrow columnar elements and the unperforated interlaminar

surfaces, the shell structure of Eothele tubulus is best described as baculate.

The presence of both orthogonal vertical and inclined bacula in the same shell

is reminiscent of the situation in Curticia? pattersonensis from the middle

Cambrian of the Great Basin (Streng and Holmer 2005). This shell structure

was interpreted by Streng et al. (2008) as intermediate between typical

baculate and orthogonal baculate shell structures. Orthogonal columnar shell

structures may be plesiomorphic for linguliform brachiopods and are

characteristic of the stem group brachiopod Mickwitzia cf. occidens from the

lower Cambrian of Greenland (Skovsted and Holmer 2003). Eothele tubulus is

currently the oldest brachiopod known with orthogonal bacula, and the

evolution of this type of shell structure thus must have started already in the

early Cambrian. The closely related middle Cambrian acrothelid, Acrothele, is

known to have a typical baculate shell structure (Cusack et al. 1999). The

presence of an orthogonal baculate shell structure in Eothele also supports

the suggestion by Streng and Holmer (2005) that the problematic family

Curticiidae is closely related to the acrothelids.

Occurrence. ─ The inferred upper lower Cambrian of an unidentified rock

unit above the Sekwi Formation, Northwest Territories, Canada; upper lower

Cambrian Forteau Formation of western Newfoundland and Kinzers

Formation of Pennsylvania.

ACKNOWLEDGMENTS

Dr R.D.K. Thomas (Lancaster, Pennsylvania) is cordially thanked for

guiding J.S. Peel in the field, making additional collections available for

examination and for information concerning Thomasville geology. Dr. M.

Streng (Uppsala) and Dr. U. Balthasar (Glasgow) provided valuable

discussions and insights into Cambrian linguloid shell structures. Constructive

reviews by two anonymous reviewers are greatly appreciated. Grants from the

Swedish Research Council (Vetenskapsrådet) are gratefully acknowledged.

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15

Figures

Fossils \ Region

Pennsylv

ania

NY

Sta

te

Quebec

Weste

rn

New

foundla

nd

North

East

Gre

enla

nd

North

Gre

enla

nd

Eothele tubulus x x

Hadrotreta sp. x x x x x x

Eoobolus priscus x x x x x

Micromitra sp. x x x

Pelagiella sp. x x x x

Yochelcionella americana x x x

Yochelcionella chinensis x x x x x

Yochelcionella greenlandica x x

Planutenia flectata x x

Conotheca australiensis x x x x x

Hyolithid sp. x x x x x x

Chancelloria sp. x x x x x x

H. micans x x x x x x

Salterella cf. mccullochi x x x x

Hexactinellid spic. x x x x

Dodecaactinella spic. x x

Echinoderm oss. x x x x x x Table 1─ Faunal content the Thomasville fauna and comparisons with coeval

faunas from eastern Laurentia. Based on Walcott 1886; Schuchert and

Dunbar 1938; Resser and Howell 1938; Lochman 1956; Landing and

Bartowski 1996; Landing et al. 2002; Skovsted 2004, 2006a; Malinky and

Skovsted 2004; Skovsted and Peel 2007.

16

FIGURE 1─ Map of North America with east Laurentian lower Cambrian

localities mentioned in the text indicated, detailed locality maps of the

Thomasville locality and generalised Cambrian stratigraphy of Pennsylvania.

A, North Greenland; B, North-East Greenland; C, western Newfoundland; D,

Taconic Allochthons of New York State; E, Thomasville, Pennsylvania.

17

FIGURE 2─ Helcionellids, hyoliths and brachiopods from the lower Kinzers

Formation, Thomasville, Pennsylvania. Unless otherwise stated, all scalebars

equal 200 µm.

2.1-2.2: Yochelcionella chinensis; USNM zzz01; 2.1, lateral view of specimen

missing snorkel; 2.2, anterior view. Scalebars equal 500 µm.

2.3-2.5: Yochelcionella americana; 2.3, USNM zzz02, lateral view; 2.4, USNM

zzz03, lateral view; 2.5, USNM zzz04, anterior view. Scalebars equal 100 µm.

2.6: Yochelcionella greenlandica; USNM zzz05, lateral view. Scalebar equalS

500 µm.

2.7: Planutenia flectata; USNM zzz06, lateral view. Scalebar equals 100 µm.

18

2.8-2.11: Pelagiella sp.; 2.8, 2.9, USNM zzz07; 2.8, apical view; 2.9, apertural

view; 2.10, 2.11, USNM zzz08; 2.10, apical view; 2.11, apertural view.

Scalebars equal 500 µm.

2.12-2.14: Conotheca australiensis; 2.12, 2.13, USNM zzz09; 2.12, lateral

view; 2.13, apertural view; 2.14, USNM zzz10, lateral view of conch with

flaring aperture.

2.15-2.16: Hyolithid conch; USNM zzz11; 2.15, view of dorsum; 2.16,

apertural view.

2.17: Micromitra sp.; USNM zzz12; internal view of ventral? valve.

2.18-2.21: Hadrotreta sp.; 2.18, USNM zzz13, ventral valve exterior; 2.19,

USNM zzz14, ventral valve interior; 2.20, USNM zzz15, obilque view of

ventral valve interior; 2.21, USNM zzz16, dorsal valve interior.

2.22: Eoobolus priscus; USNM zzz17, ventral valve interior.

19

FIGURE 3─ Small shelly fossils from the lower Kinzers Formation,

Thomasville, Pennsylvania. Unless otherwise stated, all scalebars equal 200

µm.

3.1-3.3: Salterella mccullochi; 3.1, USNM zzz18, lateral view of phosphatic

internal mould; 3.2, 3.3, USNM zzz19; 3.2, Lateral view of silicified? Conch;

3.3, apertural view.

3.4-3.6: Chancelloria sp. 3.4, 3.5, USNM zzz20; 3.4, Basal facet of

phosphatised 7+1 sclerite; 3.5, detail of 3.4 showing morphology of structures

around basal foramen of one ray, scalebar equal 100 µm; 3.6, USNM zzz21,

phosphatic internal mould of probable 7+1 sclerite missing two rays.

3.7-3.8: Dodecaactinella spicule; USNM zzz22; 3.7, detail of 3.8 showing

etched calcitic surface with dissolution faces of the crystal lattice, scalebar

equals 10 µm; 3.8, partly broken bilaterally symmetrical Y-shaped spicule.

3.9: Hexactinellid spicule; USNM zzz23, lateral view of 6-rayed spicule.

3.10-3.11: Hyolithellus sp.; 3.10, USNM zzz24, lateral view of tube fragment;

3.11, USNM zzz25, lateral view of tube fragment.

3.12-3.15: Echinoderm ossicles; 3.12, 3.13, USNM zzz25; 3.12, detail of 3.13

showing etched surface with dissolution faces of the calcite crystal lattice,

scalebar equals 20 µm; 3.13, dorsal view of ossicle composed of

monocrystaline calcite; 3.14, 3.15, USNM zzz26; 3.14, dorsal view of

secondarily phosphatised ossicle; 3.15, detail of surface of 3.14 showing

phosphatised stereome, scalebar equals 20 µm.

20

FIGURE 4─ Eothele tubulus Ushatinskaya in Voronova et al., 1987 from the

lower Kinzers Formation, Thomasville, Pennsylvania. Scalebars equal 200 µm

in 4.1,4.2,4.7,4.8,4.9,4.10,4.12,4.13,4.17, 50µ in 4.3,4.4,4.11,4.14 and 10 µm

in 4.5,4.6,4.15,4.16,4.18,4.19.

4.1-4.6: USNM zzz27; 4.1, ventral valve exterior; 4.2, oblique posterior view;

4.3, detail showing larval shell morphology; 4.4, lateral view of larval shell;

4.5, detail of larval shell ornament; 4.6, detail of adult shell ornament.

4.7-4.8: USNM zzz28; 4.7, ventral valve exterior; 4.8, lateral view.

4.9-4-11: USNM zzz29; 4.9, ventral valve exterior; 4.10, oblique posterior

view; 4.11, detail of pseudointerarea showing lenticular pedicle foramen.

21

4.12: USNM zzz30, oblique anterior view of ventral valve interior showing V-

shaped anterior muscle field and paired umbonal or transmedian

musclescars.

4.13-4-16: USNM zzz31; 4.13, posterior view of deformed ventral valve

showing lateral constriction of the shell and damaged pseudointerarea; 4.14,

detail of broken shell edge with shell structure preserved; 4.15, detail of 4.14

showing one shell layer dominated by vertical columns; 4.16, detail of 4.14

showing shell layers dominated by inclined columns.

4.17-4.19: USNM zzz32; 4.17, ventral valve interior with V-shaped anterior

muscle field; 4.18, broken shell edge showing stratified shell structure

dominated by vertical columns; 4.19, partly exfoliated shell layers showing

combination of vertical and inclined columns.