Below is a chronological list of references to Aspidella terranovica, Billings from its discovery to its acclamation as the First Named Ediacaran Body Fossil in 2000.
- in 1868 Alexander Murray collects some “obscure organic remains” from slates near St. John’s Newfoundland which he believes belong to the “Huronian system in Canada” noting that he had long had some in his possession (Murray, 1869)
- on January 29, 1872 Elkanah Billings delivers a talk before the Natural History Society of Montreal entitled ‘On some supposed fossils from the Huronian Rocks of Newfoundland.’
- a report of Billings talk appears in the March, 1872 edition of the American Journal of Science and Arts [Amer. Jour. Science, Series 3, Volume 3, No. XV, 223-224,], with the title ‘Fossils from the so-called Huronian of Newfoundland,’ states “The fossils of the Huronian are of two species. One is a broad ovate (6 lines long by 5 broad), with a ring-like border, inside of this a groove, and the interior raised roof-like, with an angular ridge or crest along the middle. In allusion to the shield-like form, a little like an oblong Patella, it is named by Billings Aspidella Terranovica. Two specimens occur on one slab of stone.”
- a report of Billings’ talk is published in April, 1872 in the Canadian Naturalist and Quarterly Journal of Science (Volume 6, New Series, Part 3, page 343): “These supposed organisms, as they are provisionally regarded, belong to two species, or at any rate present two kinds of appearances, but their affinities are at present exceedingly doubtful. A discussion ensued as to the age of the rocks in which these supposed fossils were found, Mr. Billings maintaining (with Mr. A. Murray, the Director of the Geological Survey of Newfoundland), that they are of Huronian age, and Dr. T. Sterry Hunt, that they are of a newer horizon, and belong to the base of the Primordial zone.”
- The next issue of the Canadian Naturalist and Quarterly Journal of Science (Volume 6, New Series, Part 4), published in August, 1872, contains a paper by Sterry Hunt (1872) where he discusses Murray’s work in Newfoundland and mentions Aspidella terranovica, commenting (page 437) that the rocks “yielded two species of organic forms, lately described by Mr. Billings. One of these is an Arenicolites ... and the other a patella-like shell, to which he has given the name of Aspidella Terranovica. [Amer. Jour. Science, III, iii, 223.] These, from their stratigraphical position, have been regarded as Huronian”
- The same issue of the Canadian Naturalist and Quarterly Journal of Science (Volume 6, New Series, Part 4) published in August, 1872 contains Billings (1872; 478-479) description of Aspidella terranovica, under the subheading ‘Fossils in the Huronian Rocks’:
“These are small ovate fossils five or six lines in length and about one-fourth less in width. They have a narrow ring-like border, within which there is a concave space all round. In the middle there is a longitudinal roof-like ridge, from which radiate a number of grooves to the border. The general aspect is that of a small Chiton or Patella, flattered by pressure. It is not probable, however, that they are allied to either of these genera.
Associated with these are numerous specimens of what appear to be Arenicolites spiralis, a fossil that occurs in a formation lying below the primordial rocks in Sweden. These fossils were first discovered by A. Murray, Esq., F.G.S., in 1866. Other specimens were collected by Capt. Kerr, R,N., Mr. Howley and Mr. Robertson.
They occur near St. Johns, in the Huronian. A more detailed description will be given hereafter.”
- Murray (1873) in his Report upon the geological survey of Newfoundland for the year 1872, mentions (at page 691) that “The discovery of fossil forms in the Huronian rocks of St. John's, which were recently examined and described by Mr. Billings of the Geological Survey of Canada, is not only a new and interesting geological fact, but is also of much value to the explorer while following out the structure, as it appears to mark a particular zone or horizon of the formation”; includes Billings’ full description of Aspidella terranovica (page 698); mentions (page 698) that “the presence of the Aspidilla is frequently of marked value as an indicator of the horizon”; and reports that “the past year similar organisms were found in equivalent strata in Trinity Bay, at several parts of the valley of the Rocky River, and at Ferryland, shewing its wide range laterally; in some cases literally covering extensive surfaces of the rock with forms large and small, while in others they were found scantily sprinkled here and there in isolated individual
- Ramsay (1873) considered Aspidella to be a Precambrian fossil.
-Billings (1874) in Palaeozoic Fossils, Volume II, Part 1, repeats his description of Aspidella terranovica and includes his drawing (but rotated).
- Sterry Hunt (1875a, 1875b) considered Aspidella and Arenicolites to be “organic remains” and “organic forms”.
- Dawson was not consistent as to his views on Aspidella, describing it as “The curious limpet-like objects” (1875a, 1875b), ‘the problematical Aspidella...that may have been a mollusk, allied to Patella, or some obscure form of crustacean’ (1875c), ‘peculiar fossils,” (1878), "the uncertain fossils described by Billings as Aspidella" (1888), “The peculiar fossils’ and “ the doubtful fossils”(1889). A number of Dawson’s papers figure one of Billing’s drawings of Aspidella.
- Dana in his Manual of geology (1875, Second Edition; 1880, Third Edition; 1894, Fourth Edition) considered Aspidella to be “Of undetermined relations” and “a fossil of uncertain relations”.
- While Nicholson (1876) called them “certain problematical limpet-shaped fossils”, White and Nicholson (1878) described Aspidella as “curious fossils”, noting that the “the affinities of [Aspidella] are uncertain.”
- Hitchcock (1877) had an interesting interpretation, possibly following Dawson (1875c), stating that “The Aspidella bears some resemblance to the limpet-shell or Patella, while it may have been some variety of crustacean.”
- Miller (1877) considered Aspidella to be a fossil putting it in the Class Pteropoda, but grouped it under Incertae sedis (Latin for "of uncertain placement"). Pteropoda are specialized free-swimming pelagic sea snails and sea slugs– marine gastropods.
- Milne and Murray (1877) mention that rocks that they identify as Huronian in age “are remarkable as containing fossils. The fossils are Aspidella terranovica, together with traces of organisms like Arenicolites.”
- Murray (1880) in report on a gold occurrence in Newfoundland mentions that the “The rock formation intersected by these auriferous quartz veins is of Huronian or Intermediate age, belonging to Division C of Report for 1868, or the group of strata next below the Aspidella slates of St. John's,” and the reference to the gold being in rocks below the Aspidella slates is repeated in Murray (1881), Anonymous (1881a, 1881b, 1882), Becker (1885)
- 1881: Geological survey of Newfoundland, a 536-page compilation of the annual reports 1864-1879 by Alexander Murray and James Patrick Howley is published. It contains a few minor corrections and additions.
- Barrande (1881) mentions Aspidella in his treatise on Molluscs, but considered it “de nature problématique” [Translation: of problematic nature]
- Tryon (1882) in volume 2 of his treatise on Mollusca noted that Miller had referred Aspidella to the Pteropoda , but commented that it is “a very doubtful fossil”. Tryon figures one of Billings’ drawings.
- Murray (1882) in the Report of the Geological Survey of Newfoundland for the year 1881 (a) notes that the fossil Aspidella Terranovica offers “great facilities for the ready recognition of the Huronian when tracing out the structure”, (b) mentions numerous occurrences of the Aspidella slates, and c) includes Billings’ description of Aspidella in an Appendix together with Billing’s drawing (rotated).
- Crié (1883) considered it a fossil
- Whitney and Wadsworth (1884) commented “To us, the general aspect of the fossil in question, as figured by Mr. Billings, is that of a concretion intersected by small irregular cracks, and much more resembling the so-called Septaria than anything organic.
- Whitney and Wadsworth (1884) also remarked on the variation commenting that “Specimens of Aspidella sent us by Mr. Murray, however, do not resemble in any respect the fossil figured by Mr. Billings. There are several indistinct impressions on the fragment of rock, neither of them like that fossil, and none of them necessarily of organic origin, at least so far as we are able to discover. They look more like spray markings than anything else with which we are able to compare them.”
- Zittel (1885) classified Aspidella under Mollusca, Unterklasse - Pteropoda, Ordnung - Thecosomata, Familie - Hyalaeidae, and put Aspidella in with a group of fossils that he considered “sind theils mangelhaft erhaltene, theils ungenügend charakterisirte silurische Genera.” [Translation: are partly poorly preserved, partly insufficiently characterized Silurian genera.], and made the same comments in the French language version published in 1887 (“sont des genres siluriens incomplétement conservé, ou insuffisament caractérisés”), but Aspidella was not mentioned in the English translation of his work published in 1900
- Matthew (1885a, 1885b) described Aspidella as an “organic form”.
-Laflamme (1885) figured one of Billings’ drawings of Aspidella and considered it a species,
- The American Committee for the International Geological Congress held in 1888 in London (Fraser, 1888; Dana et al., 1891), of which Dana, Fraser, Hitchcock, Hunt, Pumpelly and Winchell were the committee members, commented “The Aspidella as a fossil is dismissed as a concretion intersected by small irregular cracks.” (Likely following Whitney and Wadsworth (1884).)
- Miller (1889) includes Aspidella in Class Pteropoda, Familae Aspidellidae, provides a brief description of Aspidella, and figures one of Billings’ drawings of Aspidella
- Marcou (1890) commented that “the only specimen of an organic structure certain and indisputable is the Aspidella terranovica Billings, compared to a small Chiton or Patella, flattened by pressure.”
- Initially Walcott (1890, 1891) treated Aspidella as a fossil.
- Weston (1891 [1894] stated that “they were only concretions.”
- Almera (1891, according to Llopis Lladó, 1942; see also Unknown, 1916) and Almera and Faura I Sans (1918) reported impressions of the fossils Medusite and Aspidella in the Cambrian rocks near Barcelona
- while Van Hise (1892) describes Aspidella as a fossil whose “organic origin can not be doubted” he also references Whitney and Wadsworth (1884) where “It is denied that Aspidella and Arenicolites are of organic origin”, but earlier had reviewed Murray’s 1868 reports on the Avalon rocks of Newfoundland that Murray placed in the Huronian and commented “In one member of the group is a fossil, designated as Aspidella, of a low order of existence, which leads to the conclusion that the system is probably Cambrian.” Van Hise (1895) repeated that Aspidella as a fossil whose organic origin can not be doubted. Van Hise and Leith (1909) were inconsistent stating “The Aspidella of the Momable slates is probably of organic origin, but it may be questioned.”, mentioning that Murray had found the fossil Aspidella in Newfoundland, stating “An examination of the form known as Aspidella terranovica found in the Momable terrane of the Avalon series proved the supposed fossil to be a spherulitic concretion, and this removes it from among the possible pre-Cambrian forms of life.” and “ It contains two so-called fossils, Aspidella terranovica and Arenicolites spirales, but these have been held by Walcott not to be organic.”
- Howley (1892) describes Aspidella as “an obscure fossil organism” in the Report of the Geological Survey of Newfoundland for the year 1892 when he mentions a suites of slates “ that has been named the St. John’s slate, or Aspidella slate, from the occurrence in it of an obscure fossil organism peculiar to these rocks in Newfoundland. It has been named by Billings Palaeontologist of the Canadian Geological Survey, Aspidella Terranovica. “
- de Launay (1894) viewed Aspidella and Arenicolites as “des organismes problématiques” [Translation: problematic organisms]
- at the 1894 International Geological Congress held in Zurich, Renevier (1897) commented on the absence of well-characterized and undisputed fossils in the Precambria.. Winchell (1897) considered Aspidella to be a fossil, but Cambrian not Huronian.
- Weston (1896) comments that while St. Johns 1874 he “collected several of the so-called Aspidella. These, together with all other specimens now in the Dominion Geological museum, vary so much in form and appearance that I am afraid they also will ultimately be classed with
the concretionary forms”
- Matthew, 1898 , in a note to Packard, wrote that he had “seen Aspidella terranovica in the museum at Ottawa and doubt its organic origin. It seems to me a slickensided mud concretion striated by pressure.” He reported that he had “found similar objects in the Etcheminian olive-gray beds below the Saint John group”. Later, when summarizing life in the Precambrian and Cambrian, Matthew (1912) makes no mention of Aspidella.
- Packard (1898), in the text of his speech, describes Aspidella as a mollusc, but in a footnote calls it a “supposed fossil” and refers to Matthews note doubting its organic origin and quotes Matthew’s statement that it is slickensided mud concretion striated by pressure.
- Weston (1899) commented that while Aspidella “looks somewhat like a crushed and distorted chiton... this also is one of those doubtful forms which will be looked at shyly by the paleontologist of the present day”
- Walcott (1899) commented that Aspidella is “probably of organic origin but it may be questioned” and quoted Matthew’s (1898) note to Packard doubting its organic origin. Walcott (1899) in his Plate 27, which he described as “Figures 7, 8. — Type specimens in collection of the Geological Survey of Canada.” figured two specimens of Aspidella, which are now identified as GSC 221a and GSC 221b
- Walcott (1900) commented “A collection of the form known as Aspidella terranovica was made from the Momable terrane of the Avalon series. It proved the supposed fossil to be a spherulitic concretion, and this removes it from among the possible pre-Cambrian forms of life.”
- Trouessart (1899) in an entry in ‘La grande encyclopédie’ considered it a Cambrian fossil
- While Billings stated “The general aspect is that of a small Chiton or Patella, flattened by pressure” and cautioned that “It is not probable, however, that they are allied to either of these genera.”, this did not prevent some from classifying Aspidella as a patelloid shell, including Hutton (1898 & 1902) .
- Garde (1900) described Aspidella as “bien qu'ayant l'aspect général d'un Chiton ou d'une Patelle, aplatis par la pression, n'étaient que des concrétions de vase striée par des mouvements mécaniques” [Translation: but these, although having the general aspect of a Chiton or a Patelle, flattened by the pressure, were only concretions of mud striated by mechanical motions]
- De Lapparent (1900) commented that where some authors have wanted to see a mollusk, others viewed Aspidella as mere pressure effects. De Lapparent (1906) made the same comments and added that it has been recognized as a spheroidal concretion.
- Walcott (1901) repeated that Aspidella is inorganic in an article written in French [Translation: I was convinced on the spot that the Aspidella of Momable's schists are of inorganic origin] in a paper delivered at the the Eighth International Geological Congress at Paris held in 1900.
- Roverto (1901) called Aspidella “al fossile molto problematico” [translation: the very problematical fossil]
- Sir Archibald Geikie (1902) called it a fossil, but Geikie (1903) on reviewing possible Precambrian fossils, makes no mention of Aspidella
- Merrill (1903) mentions that the Museum of the Geological Survey of Newfoundland, in St. John’s, has specimens of “Arenicolites and Aspidella from Newfoundland, Oldhamia radiata from Ireland.”
- Xambeu (1906) considered Aspidella to be a genera of Pterapods – pelagic molluscs, but Cambrian.
- Chamberlin and Salisbury (1907) in their textbook ‘Geology. Volume II, Earth History’ review life during the Proterozoic Era and make no mention of Aspidella
- Solas (1909) commented ‘Aspidella is plainly organic’
- Charles Schuchert (1910) collects specimens of Aspidella from St. John’s, Newfoundland for the Yale University collection. Schuchert and Dunbar study the rocks of Newfoundland, and Schuchert and Dunbar (1934) author a publication entitled ‘Stratigraphy of Western Newfoundland’, which does not cover the rocks where Aspidella has been found, and accordingly make no mention of Aspidella.
- Walcott (1910) did not mention Aspidella in his summary of Precambrian fossils.
- in papers at the 1910 International Geological Congress in Stockholm, Matthew (1912) briefly reviews organic remains in the Precambrian making no mention of Aspidella, Evans (1912) mentions Beltina and Chuaria but not Aspidella, and neither Sollas (1912) nor Sederholm (1912) mention Aspidella
- Blackwelder and Barrows (1911) in their text ‘Elements of Geology’ very briefly review life in the Proterozoic and make no mention of Aspidella
- Arldt (1912) considered Aspidella a fossil commenting “Auf der Halbinsel Avalon
kommen zusammen ... runde Schalen von Aspidella vor, die wie flachgedrückte Käferschnecken (Chiton) oder Napf-schnecken (Patella) aussehen ; beide primitiven Ordnungen angehörend” [Translation: On the Avalon peninsula there are also round shells of Aspidella, which look like flattened beetle snails (chiton) or tortoise snails (patella); belonging to both primitive orders]
- Perret (1913) reviewed whether Aspidella was a fossil mollusc or concretion, but chose not to take sides.
- Wurm (1914) considered Aspidella to be a probable Precambrian organic remain, commenting “Leider sind die Bemühungen, organische Reste zu finden, ziemlich erfolglos geblieben. Nur aus den sog. Momable-Schichten ist von Billings ein Rest angegeben worden, den er Aspidella terranovica nennt und der wohl organischen Ursprungs ist. Es handelt sich um ovale Körper, die in der Mitte einen auggewulsteten Ringe besitzen, von dem radiale Rinnen nach dem Rand ziehen.” [Translation: Unfortunately, efforts to find organic remains have been unsuccessful. Only from the so-called Momable layers has been given by Billings a remainder, which he calls Aspidella terranovica and which is probably of organic origin. These are oval bodies with rings in the middle, from which radial grooves run to the edge.]
- Cleland (1916) in his textbook ‘Geology, physical and historical’ reviewed life in the Proterozoic and made no mention of Aspidella
- Buddington (1919) considered Aspidella to be a “possible fossil”.
- Walther (1919) in his text ‘Allgemeine palaeontologie : I. Teil: Die fossilien als Einschlüsse der Gesteine’ reviewed life in the Precambrian and made no mention of Aspidella
- Dacqué (1921) considered Aspidella to be an Algonkian organic remain.
- Grabau (1921) in his ‘A Text Book Of Geology Part II Historical Geology’ reviews precambrian rocks and evidence of life therein, and comments “On the Avalon Peninsula of eastern Newfoundland there is an extensive series of folded quartzites, slates, and other rocks only slightly metamorphosed, and carrying in some cases, indistinct organic remains.”
- Clark (1923) commented that he did “ not hesitate to state that he believes it inorganic in origin. A tentative explanation is that these structures represent the sites of vents from which gas escaped...”
- Ruedemann (1925) remarked that “Although Aspidella terranovica appears in some of the older textbooks as a Precambrian fossil, it seems to have early fallen under suspicion. It is not any more cited by G. F. Matthew among the Upper Huronian Fossils of Newfoundland ... and Thomas H. Clark has more recently ... declared these structures to be inorganic origin and probably marking the sites of vent so escaping gas.”
- Metzger (1927) considered Aspidella, like Walcott’s Chuaria, to be “Fraglicher Natur” [Translation: of questionable nature]
- David (1928) appeared to follow Walcott, commenting “Aspidella terranovica, Billings, from Momable slates, Newfoundland, probably inorganic.”
- Windhausen (1931) considered Aspidella to be a fossil whose organic character was beyond doubt.
- Dr. Morley Wilson (1931), according to Hofmann (1971), gives no opinion as to whether Aspidella is organic or inorganic, and “quotes Matthew’s (1898) opinion”
- Roy (1932) considered Aspidella to be an obscure fossil.
- Schuchert and Dunbar (1933) in their Textbook of geology, Part II, Third Edition, review life in the Precambrian and make no mention of Aspidella
- Dacqué (1935) in his text Organische Morphologie und Paläontologie mentions Aspidella at pages 311 and 314 in his review of Precambrian life, but those pages are not available on Google
- Dr. Morley Wilson (1939) commented that “Aspidella terranovica is a small ovate form discovered by Murray ... and named by Billings. G.F. Matthew, according to a quotation from a letter published by A.S. Packard, has stated that Aspidella seemed to him to be ‘a slickensided mud concretion striated by pressure’”
- von Bubnoff (1941) includes one of Walcott’s drawings of Aspidella in his figure 38 – Präkambrische Reste aus Nordamerika [Translation: Precambrian remains from North America]
- Miller (1942) in his text ‘An Introduction To Historical Geology’ briefly reviews Proterozoic life, but makes no mention of Aspidella
- Raymond (1947) reviewed the evidence of life in the Pre-Cambrian and did not mention Aspidella.
- Rankama (1948) commented “Since the structures of Eozoon canadense, Aspidella terranovica, Atikokania lawsoni and A. irregularis have been proved to be of inorganic origin, the role of the so-far oldest remains of life may be attributed to the calcareous algae of the genus Collenia, described by Fenton...”
- Hayes (1948) commented that collection of the form known as Aspidella from the Momable terrane of the Avalon series “proved the supposed fossil to be a spherulitic concretion, and this removes it from among the possible pre-Cambrian forms of life.”
- Dunbar (1949) in his textbook ‘Historical Geology’ reviewed life before the Cambrian and made no mention of Aspidella
- Kuhn (1949) in his Lehrbuch der Paläozoologie, discusses the fossil Patella and comments “Aspidella, steht Patella nahe, Algonkium”, which I translate as ‘Aspidella from the Algonkian [now, Proterozoic] is close to Patella’.
- an author (Unknown, 1949) in a a review of life in the Precambrian, classified Eozoon canadense, Aspidella terranovica and Atikokania Lawsoni as “les accidents minéralogiques” [translation: mineralogical accidents]
- Moore (1951) in his text ‘Historical Geology” reviews life in the Cryptozoic Eon, and makes no mention of Aspidella.
- Rose (1952) commented that “The possible fossil Aspidella has been declared an inorganic concretion,”
- Richards (1953) commented “Aspidella terranovica is a small ovate form discovered by MURRAY in the Momable slates of the Avalonian series of Newfoundland and named by BILLINGS. G. F. Mattews, according to a quotation from a letter published by A. S. PACKARD, has stated that Aspidella seemed to him to be "a slickensided mud concretion striated by pressure" rather ... the mode of origin of Aspidella has not been discussed since its discovery was announced by MURRAY in 1872.”
- Whittard (1953) reviewed the evidence of life in the Precambrian and did not mention Aspidella
- Schindewolf (1956), according to Hofmann (1971), described Aspidella as “Diagenic; pressure cones or buckling through escaping gas bubbles”;
- von Bubnoff (1956, Third edition) again includes one of Walcott’s drawings of Aspidella in his figure 38 – Präkambrische Reste aus Nordamerika [Translation Precambrian remains from North America]
- Dr. Alice E. Wilson (1957) commented “Billings (1873, 1874) described and illustrated by drawings (not photographs) some forms from the “Huronian” near St. John’s, Newfoundland. He named them Aspidella terranovica. ... Aspidella terranovica is still in storage. No tests were ever made upon the specimens. Matthew (1898) in a letter to A. S. Packard states that ‘Aspidella terranovica appears to be a slickensided mud concretion striated by pressure.’ Walcott (1899) figures a specimen as questionably Aspidella though elsewhere he cites Matthew’s opinion, and suggested that ‘they may be spherulitic concretions.’ The form has not been mentioned in the literature since.”
- Shevyrev’s (1962) review of reported occurrences of Precambrian fossils did not reveal “evidence of metazoan life other than the impressions of soft-bodied organisms of the Ediacaria fauna (S. Australia) and the similar fossils at Charnwood Forest (England) and in the Nama Series of Southwest Africa.”
- Häntzschel (1962) describes Aspidella under the heading ‘Fossils Probably of Inorganic Origin’ as follows: Aspidella Billings, 1872 [*A. terranovica]. Small, ovate, narrow ringlike border; having general aspect of small Patella flattened by pressure (Schindewolf, 1956) . [Regarded by Matthew (1898) as slickensided mud concretion striated by pressure; somewhat similar to Guilielmites Geinitz.].
- Häntzschel (1962) figures Walcott’s two photographs of Aspidella (namely GSC 221a and GSC 221b) rather than Billings’ drawing.
- Later in that publication Häntzschell (1962) describes “Guilielmites Geinitz, 1858 ... Ellipsoidal bodies, 1 or 2 cm. in diameter; ...most authors ... consider them to be of inorganic origin (concretions or similar diagenetic structures);” and his photographs of Guilielmites on plate 147 resemble Aspidella
- Glaessner (1962), according to Hofmann (1971), described Aspidella as inorganic;
- Häntzschel (1965), according to Hofmann (1971), described Aspidella as “inorganic; pressure cone or gas bubble;”
- Cowie (1967) reviewed life in Pre-Cambrian and early Cambrian times, but did not mention Aspidella
- Cloud (1968) in an Appendix entitled ‘Some Reported Precambrian Metazoa and Parazoa of Dubious Age or Nature’, lists Aspidella Billings with the interpretation “Compaction and spall marks.”
- R. D. Hughes , according to Hsu (1972), considered that Aspidella was a jellyfish comparable with the medusoid of the late Precambrian Ediacara fauna of South Australia described by Glaessner and Wade (1966, 1968), [ Hughes and Greene had a grant to study “Aspidella terranovica Billings - a Precambrian medusa?” – See Anonymous (1964) ; and note that Hughes and Greene collected a specimen of Aspidella terranovica, GSC type 24371, that is figured in Hofmann (1971 & 1992)]
- McCartney (1967) notes that Murray and Howley had mapped rocks in the area he was mapping “as the Aspidella slates”, but does not comment on Aspidella
- Bruckner (1969) commented “In these shale-sandstone alternations, Aspidella terranovica Billings is found; it is uncertain, however, whether these jellyfishlike imprints are true fossils or phenomena of inorganic origin (Hantzschel, 1962, p. 232).”
- Goldring (1969) commented “Anderson and Misra mention the doubtful Aspidella trerranovica Billings. This though common, is definitely inorganic. Sectioning shows that many specimens are water or gas -escape structures. Others are partly attributable to the manner in which the highly lithified clay and silt grade rock has parted along a changing stratigraphic level, particularly around load and scour structures.” Goldring , according to Hsu (1972), had examined Hsu’ s collection of specimens of Aspidella before asserting that they were load structures and definitely not fossils.
- Misra (1969) mentions “the doubtful fossil Aspidella terranovica Billings from the St. John's Formation", and described "Leaf-Shaped Organisms" comprised of “three parts: a main body having leaf-shaped structure (Pls. 3B and 6D) and needle-shaped projection (Pls. 1D,7A, and Fig. 2) ; an stalk (Pls. 4B and 6D); and a round base attached to the stalk." ..."The animals in some cases were broken from the base and moved slightly in the direction of the currents, leaving the disc-shaped base behind (Pl. 1H)"
- Unknown (1970) commented “Autoren erwähnte Aspidella terranovica Billings 1872 gennant, die sicher anorganishchen Ursprungs ist. Sie wurde schon vor langem als Druckkegel oder Gasblasenkrater gedeutet.” [Translation: the authors mentioned Aspidella terranovica Billings 1872, which is certainly of inorganic origin. It was long ago interpreted as pressure cone or gas bubble crater]
- Hofmann (1971) provides a table summarizing earlier references to Aspidella, noting that “the structures have been variously interpreted as organic (mollusks, crustaceans) and inorganic (striated concretions, sites of gas vents, pressure cones, gas bubble craters, spall marks)”, and provides a photograph showing an aspidella-like radial pattern with medial ridge produced experimentally. He concluded that “The elongation of Aspidella can reasonably be attributed to tectonic deformation, and the structure itself can be interpreted to mechanical origin resulting from differential movement of mud”, summarizing his observations as “of mechanical origin; focussed surfaces of rupture.”
- Hofmann (1971) includes photographs of GSC 221a and GSC 221b, the specimens figured by Walcott (1899) in Plate 27, Figures 7, 8 as, Hofmann (1971) Plate 5, figures 2 and 3, noting that these two specimens “which may not belong to the ‘species’ but are labelled Aspidella terranovica, are in the same collection as the plastotype.”
- Hsu (1972), in an unpublished thesis, divided the Aspidella like markings and associated concentric discs into six types based on morphological features (such as relief, size, shape, number of concentric rings, central longitudinal groove, and radial lines), notes that “The markings are round to elliptical in shape and both forms may occur on the same surface...The elliptical forms clearly show a preferred orientation on bedding surfaces.... The author considers that the elongation represents stretching due to tectonic deformation;”, notes that “There is transition in morphology between the six types;” and concluded that “Aspidella terranovica Billings 1872 and associated surface markings ... are considered to be inorganic sedimentary structures such as load casts and gas- or water-escape structure”
- Häntzschel (1975) commented “Ovate structures, up to 3 by 4 cm. in size; rooflike ridge in central area of ellipse, with fine radial ridges and grooves extending to periphery; narrow ringlike border; mostly on bedding planes all oriented in one direction; having general aspect of small Patella flattened by pressure. [BILLINGS (1872) regarded Aspidella as fossil; MATTHEW (in PACKARD, 1898) interpreted it as slickensided mud concretions striated by pressure; WALCOTT (1899) and VAN HISE & LEITH (1909) were doubtful whether organic or inorganic; regarded by SCHINDEWOLF (1956) as inorganic and identical with Guilielmites GEINITZ; according to GOLDRING (1969), partly attributable to water- or gas-escape structures and interpreted by CLOUD (1968) as compaction and spall marks; according to HOFMANN (1971) inorganic, focused surfaces of rupture; for detailed discussion, complete summary of references, and various interpretations, see HOFMANN (1971, p. 16). ”
- in an article in a Polish journal published in 1977, Kozlowska-Koch commented “The doubtful genera Aspidella Billings from the Precambrian of Newfoundland and Chuaria Walcott, which on account of their form and size were originally regards as belonging to the forminifera, turned out to be concretions as well.”
- Williams and King (1979) report on the Mistaken point fauna of the Trepassey map area, mentioning that “Disc-like impressions are of several varieties (Fig. 14C). Most are comparable with Charniodiscus concentricus Ford (1958), from the Precambrian Charnian succession of Leicestershire. A rather rare variety at Mistaken Point, with numerous concentric annulations, bears close resemblance to an impression in the Charnwood succession described by Ford (1968, p. 13) and thought to resemble Cyclomedusa davidi Sprigg, which is found in the Ediacara fauna of Australia as well. Disc-like forms with radial depressions (Fig. 14B) are probably medusoid impressions. Frond-like impressions at Mistaken Point, which resemble Charnia masoni Ford (1958), are in places joined by a stalk to the disc-like forms (Charniodiscus), and thus may represent one organism (Fig. l 4E). The disc presumably represents a circular anchorage for the once-upright frondlike form.”
- Williams and King (1979) also discuss the Fermeuse Formation and mention that "Circular structures on bedding surfaces, from 1 to 10 cm diameter, were previously interpreted as the trace fossil Aspidella terranovica Billings, 1872. These occur toward the top of the formation with the best examples in the map area at Clear Cove on the north side of Fermeuse Harbour."
- the author (Unknown, 1979) of a paper on the Jodhpur Group of rocks, India, commented “Our specimens compare well, at least superficially, with Aspidella Billings, 1872– a “fossil” probably of inorganic origin but these do not display the characteristic radial patterns of Aspidella"
- Yochelson (1979a), in an article summarizing Walcott’s career, reports on Walcott’s examination of Aspidella in Newfoundland and appears to endorse Walcott’s view that Aspidella is inorganic
- Yochelson (1979b) mentions both Aspidella and Aspidellidae in his review of Mollusca and Mollusc-like Groups
- Ford (1979) reviews Ediacaran Metazoans, but does not mention Aspidella
- Brasier (1979) reviews the Edicaran medusoids, including those from Newfoundland, and does not mention Aspidella
- King (1980) commented that "Aspidella terranovica, Billings, 1872, present in the shales, is thought to be inorganic although some of the larger varieties may be medusoid impressions."
- Goldring (1980) stated that the “medusa Aspidella” was “la estructura de un excape de aqua o de gas” [translation: an escape structure for water or gas]
- The Geological Association of Canada (Anderson and King, 1980) had a field trip with a stop at Ferryland where “Numerous examples of the pseudo-fossil Aspidella terranovica Billings, up to 6 cm in diameter, can be seen on bedding surfaces of steeply east-dipping shales of the St. John’s Group.”
- Hofmann (1981) in his review of the 70's makes no mention of Aspidella, but in his discussion of megafossils discusses new occurrences of large medusoids
- Kauffman and Steidtmann (1981, page 925) reviewed Precambrian trace fossils and commented “g, small subcircular structures, Aspidella terranovica Billings, interpreted by Hofmann (1971, Pl 4, figs. 1-6) as having been mechanically produced except for one unique specimen with concentric “wrinkles” and a coiled apex having apparent characteristics of simple mollusks (fide, Walcott, 1899, Pl. 27, fig. 7); this trace has never been explained.”
- Vidal (1984) reviews Precambrian life (stromatolites; Gurich, Namibia; Sprigg, Australia) and does not mention Aspidella
- Crimes (1984) commented “Aspidella is a case in point: it occurs very widely and is abundant at certain late Precambrian stratigraphic levels in Newfoundland and has been referred by some to gas bubbles and by others to a mechanical origin. But why …”
- Glaessner (1984, p. 93-97) in a review of Precambrian fauna covers Newfoundland highlighting the Mistaken Point Formation and discusses the disc-like impressions, but does not mention Aspidella
- Cloud (1985) stated that “Walcott (1883) reported the first genuine body fossil ever to be described from pre-Phanerozoic rocks. He referred to it as ‘a small Dicinoid shell,’ named 16 years later (Walcott, 1899) as Churaria circularis,...” Cloud makes no mention of Aspidella.
- Sun (1986) comments that “The type species C. davidi Sprigg and C. radiata Sprigg are considered as a single species because of differences due to preservation.”
- Hofmann (1987) commented “Although simple metazoans may have been found early on in the Newfoundland succession (Aspidella, Billings, 1872), these have been regarded as doubtful by many workers, but they should be restudied to ascertain whether they are not, indeed, real fossils.”
- Landing et al. (1988) in papers on and a Field Trip in the Avalon Peninsula to look at Ediacaran and Cambrian fauna and trace fossils have a stop at Ferryland where “numerous examples of the pseudofossil Aspidella terranovica Billings, 1872, are present on bedding surfaces of steeply eastdipping shales of the St. John’s Group,” and figure a “disc-like form with concentric annulations” from the Mistaken Point Formation
- Conway Morris (1989) mentions the “medusoid-like ?pseudofossil Aspidella terranovica” and the “pseudofossil Aspidella” from the Fermeuse Formation (St. John’s Group) near Ferryland, Avalon Peninsula
- Tchoumatchenco and Sapunov (1989) report finding Aspidella in marble in Bulgaria.
- Jenkins (1989) commented “It seems likely that Aspidella is organic (Jenkins 1989b)”
- King (1990) reported “ problematical circular to oval markings ... They were interpreted by early workers as the trace fossil Aspidella terranovica, Billings, 1872. A detailed account and discussion of these markings is in Hsu (1972). ... Commonly associated with Aspidella are larger disc-like varieties that resemble holdfasts; some forms may be medusoid impressions.” King (1990) also commented on the ‘Mistaken Point Formation' noting it was “profusely fossiliferous having a variety of frond-like and disc-like impressions”
- McMenamin and Schulte McMenamin (1990) review Ediacaran fauna and make no mention of Aspidella
- Seilacher (1990) collects specimens of Aspidella from a roadcut on west side of Newfoundland Rt 10, immediately North of Ferryland Museum, Ferryland, for the Yale museum
- Hofmann et al. (1991) examined an assemblage of fossil discoids of variable morphology from the Miette Group, British Columbia, noting that they were “similar to a number of discoids such as Chamiodiscus, Cyclomedusa, Medusinites, Paliella, Spriggia, and concentrically patterned forms from the Conception Group of Newfoundland illustrated by Walcott (1899, P1.27, fig. 7) as Aspidella terranovica; ... The specimen with radial markings illustrated by Walcott, however, does not have the morphology of typical A. terranovica, which exhibits a strong longitudinal roof-like ridge occupying the central portion at or near the position of the longer axis of the ellipse of each specimen; fine radial ridges and grooves emanate not from a point or small central area as in Irridinitus but from along most of the length of the roof-like ridge. Both genera may be closely related, and it is possible that I. multiradiatus may eventually be shown to be a second species of Aspidella. ... Aspidella has been variously interpreted as both biologic and nonbiologic ... Hofmann (1971, 1972) regarded it as a dubiofossil, probably of mechanical origin. New materials found since then in Newfoundland, as well as collections of similar material from eastern Europe and the Rocky Mountains ... suggest that a biological interpretation should be reconsidered for Aspidella.
- Hofmann (1992) in a short article entitled ‘Megascopic Dubiofossils’ describes a group of dubiofossils which “includes various discoidal markings, sometimes with indistinct radial patterns, resembling bona fide fossils” an example of which is Aspidella from Newfoundland. He also mentions that “Although most authors have treated it as nonbiologic... the evidence now remains inconclusive...”. He includes a photograph of Aspidella terranovica from the St. John’s Group, Newfoundland (GSC type 24371) and states that “Aspidella needs restudy.”
- Schopf (1992) reviewed Ediacaran body fossils and did not mention Aspidella
- Jenkins (1992) commented "The widely occurring, supposed pseudofossil Aspidella terranovica Billings, 1872, present in intercalated thin sandstones and shales or ripple-bedded, flaggy sandstones near the top of the Fermeuse Formation, also show annulation and occasional radial structures similar to C. davidi, and a small central plug of sand (Conway Morris, 1989a) resembles the fill of attachment stalks of such sedentary, discoidal forms in the Flinders Ranges. ... I believe that A. terranovica is probably organic (Jenkins, 1989), and that the larger discoidal forms associated with it in the Ferrylands areas may be equivalents of the "medusiform" remains of South Australia;"
- Farmer et al. (1992) describe an assemblage of discoidal megafossils, noting that “Preservational variations are conspicuous within many Ediacaran discoidal fossils, and some taxa ... have been applied very broadly.” They do not mention Aspidella
- Runnegar (1992) in a table listing formally described species of Vendian soft-bodied metazoans that comprise the Ediacara fauna, includes
- Aspidella costata, Vodanyuk, 1989, Olenyok Uplift
- Aspidella hatyspytia, Vodanyuk, 1989, Olenyok Uplift
- Aspidella terranovica, Billings, 1872, Newfoundland, pseudofossil
- Reed et al. (1993 ) in a summary of the Precambrian in the Conterminous U.S., mention medusa-like markings, and include a 77 page appendix on Precambrian Paleontology, but do not mention Aspidella
- Fedonkin (1994) reviews Vendian body fossils and trace fossils, and makes no mention of Aspidella
- Myrow (1995) noted that “Problematic discoidal structures referable to Aspidella terranovica occur within the Fermeuse Formation of the St. John's Group. These problematica, which have a central sandy plug and both annulations and rare radial structures, have been interpreted as both inorganic features (Hofmann, 1971 ; Conway Morris, 1989 ) and as substrate-attached medusoid body fossils (King, 1980; Jenkins, 1992 ).,”
- Runnegar (1995) states that “The Ediacara ‘fauna’ was discovered independently in Newfoundland (Billings 1872), Namibia (Gürich 1929) and South Australia (Sprigg 1947), and then found in many other parts of the world (Glaessner 1984). Ironically, the first Ediacaran fossil to appear in the scientific literature, Aspidella terranovica Billings 1872, was among the last to be admitted to the club. Following a long tradition, Hofmann (1971) considered...”
- Crimes et al. (1995) commented “Similar structures, such as Aspidella terranovica Billings 1872, have been regarded as inorganic by some workers and described as water or gas escape structures or concretions (see Hofmann 1971, figure 5). Recent opinion is, however, more inclined to regard Aspidella ...”
- Fenton et al. (1996) review Precambrian remains, with an extensive discussion of stromatolites, and mention Ediacara fauna, but do not mention Aspidella
- Crimes and Fedonkin (1996) in a brief review of Proterozoic and Phanerozoic discs note that “structures have been recorded as Aspidella by Vodanjuk (1989) from the Khatyspyt Formation of the Olenik uplift, Siberia regarded as late Proterozoic” and mention “An example from the late Proterozoic of Newfoundland recorded as Aspidella terranovica, Walcott 1899", noting that “There is clearly a need for a thorough re-examination of all these circular structures...”
- Williams et al. (1996) mention that “Fossils of soft-bodied metazoans are present in the Trepassey Formation and the lowest part of the Fermeuse Formation. A variety of problematic markings, including those named Aspidella terranovica (Billings, 1872) occur near the top of the Fermeuse Formation. Some of these are concentric markings that resemble medusoid impressions, but they are probably inorganic in origin (Hsu, 1972).”
- McMenamin (1998) reviews Ediacaran fossils and notes that “The Precambrian fossil Aspidella has the same oval shape, and may represent a nongliding version of Vermiforma.”
- Clarkson (1998) reviews Ediacaran fauna and trace fossils and does not mention Aspidella
- Thompson and Bailey (1998), according to Thompson and Bowring (2000), reported Aspidella in Argillite at Hewitts Cove, Hingham, Massachusetts
- Hofmann (1998) makes no mention of Aspidella in the text of his article summarizing Precambrian fossils of North America, includes Aspidella in his chart of Fossils and Dubiofossils but as a dubiofossil (Figure 4.1, Sheet 2, Occurrence 242), includes Billings’ papers on Aspidella in his Bibliography of occurrences of Fossils and Dubiofossils, and figures Ediacaria flindersi and small discs of Cyclomedusa or Charnodiscus as part of his paper
- Yochelson (1998), in his biography of Walcott, provides Walcott’s diary entry when Walcott looked at Aspidella in the slates at Ferryland: “A collection of the form known as Aspidella terranovica was made from the Momable terrane of the Avalon series. It prove the supposed fossil to be spherulitic concretion, and this removes it from among the possible pre-Cambrian forms of life” (Walcott 1900b, 5). Yochelson added “That was a little tidbit to add to the store of knowledge”.
- Narbonne and Gehling (1998) presented a paper entitled ‘Is Aspidella the first described Ediacaran Body Fossil"
- Waggoner (1998), in an unpublished thesis, commented “Two decades later, Billings (1873, 1874) described Aspidella terranovica from Newfoundland, noting that it had been found as early as 1860. Although considered at best a dubiofossil by most authorities since then (Walcott, 1899; Wilson, 1957; Hofmann 1982; Conway Morris 1989b), recent studies... . I have included in this analysis the “medusoid” Aspidella; this has often been considered a pseudofossil or dubiofossil, but the most recent studies...”
- Waggoner (1999) included Aspidella in his dataset of Ediacara biota and commented “Recently, Narbonne and Gehling (1998) have made what I believe to be a convincing case that the form Aspidella, which has been usually considered to be abiogenic, is a true fossil. Furthermore, it is so variable in morphology that these authors consider it the senior synonym of most of the “medusoid” taxa. This may well be correct, but much more careful work will be needed to work out the taxonomy of “medusoids,” which is already in some confusion.
- Hagadorn et al. (2000) reported “both discoidal and frondlike fossils comparable to Ediacaran taxa from the western edge of the Great Basin” and opined that “the taxonomy of simpler Ediacaran “medusoids’ is in of serious disarray; existing taxonomy is probably highly oversplit, and many, if not most, proposed ‘medusoid’ genera probably represent preservational variants of identical organisms (Jenkins, 1992; Narbonne and Gehling, 1998).”
- Cope (2000) commented that Aspidella had been “discussed by many authors and most have concluded that it was a pseudofossil; this view persisted until very recently following a major review by Hofmann (1971) but recently specimens have been found from the Avalon Peninsula of Newfoundland that show that the genus bears considerable similarities to Cyclomedusa, and Aspidella has been re-interpreted as a benthic medusoid (Narbonne and Gehling, 1998) thus confirming Billings’ (1872) original contention that it was an animal fossil.”
- Gehling, Narbonne, and Anderson (2000) in a paper entitled ‘The first named Ediacaran body fossil, Aspidella terranovica’ report that they “examined thousands of specimen in the field and studied many hundreds of specimens in detail in the laboratory”, conclude that Aspidella represents a wide variety of preservational morphs, and confirm that it is a body fossil with organic origins.
Additional Comments
It is worth noting that:
- Sir William Logan retired as Director of the Geological Survey of Canada on 30 Nov. 1869, taking up residence in Wales, but returned to Canada a number of times including for a few months in 1871 when he assumed temporary directorship of the GSC
- Sir William Logan died on June 22, 1875 (aged 77)
- Elkanah Billings died June 14, 1876 (aged 56) without having prepared a more detailed description of Aspidella terranovica
- Alexander Murray died December 18, 1884 (aged 74)
Christopher Brett
Ottawa, Ontario
References and Suggested Reading
Most references are appended to my following two blog postingsWednesday, May 1, 2019
Photographs of GSC 221, one of Alexander Murray’s specimens of Aspidella terranovica, Billings 1872
Friday, March 8, 2019
Concentric Structures in the Sedimentary Rocks of Lanark County, Ontario that are identical to the Ediacaran Holdfast Aspidella
Additions since the original post are below.
McMenamin, Mark A. S. (1998)
The Garden of Ediacara: Discovering the Earliest Complex Life. Columbia University Press. 368 pages.
Cloud, Preston E., Jr. ,1968
Pre-Metazoan evolution and the origins of the Metazoa. Chapter 1, pages 1-72 in Ellen T. Drake, editor, Evolution and Environment, Yale University Press, Princeton, New Jersey. 470 pp.
