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Found 23 results

  1. merycoidont lectotype

    madermerycod21257-12488-1-PB.pdf Horrible mistake:of course it's merycoidont The "click and hold option to edit title "doesn't seem to work? EDIT As somone famous once said : "I stand by the mistakes I've made"
  2. Old news

    As far As I could ascertain, not posted yet edit: Amazing Czech Open-Access Pdf Library on this very forum Posted by Piranha in 2013 you live & learn Šnajdr M. (1983): Revision of the trilobite type material of I.Hawle and A. J. C. Corda, 1847 Sborník Národního muzea v Praze, řada B - Přírodní vědy 39 (3): 129. [PDF fulltext] NB 35, Mb or thereabouts TAXONOMY warning:This is from 1983,remember!!
  3. Are Mosasaurs considered lizards?
  4. Taxonomic Vandals

    A Few Bad Scientists Are Threatening to Topple Taxonomy - Smithsonian https://apple.news/AQu_Npdw-SUyRMHleDgGc8gSmithsonian article thought this was interesting and outrageous
  5. here What NOT to expect: it's not a "pictorial atlas of...",far from it. Expect character matrices,cladograms. Any part dealing with ptychopariids might have been published already ,BTW
  6. After this horrendous attempt at a triple pun,things can only deteriorate,right? The list of species in the tags i have kept to a bare bones minimum,for clarity's sake i MIGHT not have posted this,but it figures tooth rows. Shark cognoscendi prolly already have this one(and the others by Bass)I'm sure. SO,no need to post those others orrep38a.pdf
  7. revisonary tactics

    edit: mind you,this one is fairly recent streetcaldhoffmannii_squammosrevisi!us.pdf
  8. ancient urchin

    Yes,L.& E. http://www.thefossilforum.com/index.php?/topic/65304-archaeocidaris-teeth-and-other-bits-uk/#comment-683845 http://www.thefossilforum.com/index.php?/topic/41735-another-quiz/#comment-455460
  9. Is it possible that not all the creatures we call fish are actually fish?
  10. bivalve biogeography,Neogene

    pelecypod/lamellibranch enthousiasts,take note NB: barring extraordinary events,this link will be gone 12-14 months from now,given its nature The first author doth know his bivalves,is my experience . He tends to go for the larger ones(ostreids/Lithiotis,etc) Well illustrated,as might be expected NOTA BENE two: largish download,ca 36 Mb
  11. Pliocene mollusca,USA

    Camp Might have been posted already....If so,all credits to the previous poster
  12. The best way to include fossils in the 'tree of life' January 10, 2017 http://www.bristol.ac.uk/news/2017/january/tree-of-life.html http://phys.org/news/2017-01-fossils-tree-life.html Puttick, M. N,., J. E. O'Reilly, A. R. Tanner, and others, 2017, Uncertain- tree: discriminating among competing approaches to the phylogenetic analysis of phenotype data, Proceedings of the Royal Society B. Published 11 January 2017.DOI: 10.1098/rspb.2016.2290 http://rspb.royalsocietypublishing.org/content/284/1846/20162290 Yours, Paul H.
  13. Does anyone know where I can see/get a full copy of this paper? The generic taxonomy of Pennsylvanian age marattialean fern frond adpressions Cleal, Christopher J., Palaeontographica Abteilung B Volume 292 Issue 1-3 (2015), p. 1 – 21 Jan 23, 2015 Thanks, Chris
  14. ichthyosaur diversity

    https://peerj.com/articles/2604.pdf
  15. Smith on T rex dentition

    http://www.bioone.org/doi/pdf/10.1671/0272-4634(2005)025[0865%3AHITRIF]2.0.CO%3B2 If it's been posted already,my apologies to the previous poster. However,i don't this one want to sink into relative obscurity
  16. These are a few of the pdf files (and a few Microsoft Word documents) that I've accumulated in my web browsing. MOST of these are hyperlinked to their source. If you want one that is not hyperlinked or if the link isn't working, e-mail me at joegallo1954@gmail.com and I'll be happy to send it to you. Please note that this list will be updated continuously as I find more available resources. All of these files are freely available on the Internet so there should be no copyright issues. Articles with author names in RED are new additions since September 10, 2016. Phylum Brachiopoda - The Lamp Shells. General Brachiopods General Brachiopoda - Asia/Malaysia/Pacific Islands Cooper, G.A. (1978). Tertiary and Quaternary Brachiopods from the Southwest Pacific. Smithsonian Contributions to Paleontobiology, Number 38. Khan, F.R. and J. Afzal (2005). Comparative Study of Brachiopods of Chhidru Formation from Zaluch and Nammal Sections, Western Salt Range, Pakistan. Pakistan Journal of Hydrocarbon Research, Vol.15. Shu-Zhong, S., et al. (2006). Brachiopod diversity patterns from Carboniferous to Triassic in South China. Geological Journal, 41. General Brachiopoda - Australia/New Zealand Allan, R.S. (1945). Palaeozoic and Mesozoic Brachiopod Faunas in New Zealand: with an Index to the Genera and Species.Transactions of the Royal Society of New Zealand, Vol.75, Part I. General Brachiopoda - Europe (including Greenland) Cocks, L.R.M. (1979). New Acrotretacean Brachiopods from the Palaeozoic of Britain and Austria. Palaeontology, Vol.22, Part 1. Copper, P. (1973). Bifida and Kayseria (Brachiopoda) and Their Affinity. Palaeontology, Vol.16, Part 1. Hanken, N.-M., and D.A.T. Harper (1985). The Taxonomy, Shell Structure, and Palaeoecology of the Trimerellid Brachiopod Gasconsia Northrop. Palaeontology, Vol.28, Part 2. General Brachiopoda - North America Alexander, R.R. (1977). Growth, Morphology and Ecology of Paleozoic and Mesozoic Opportunistic Species of Brachiopods from Idaho-Utah. Journal of Paleontology, Vol.51, Number 6. Anderson, E.J. and J.H. Makurath (1973). Palaeoecology of Appalachian Gypidulid Brachiopods. Palaeontology, Vol.16, Part 2. Cooper, G.A. (1988).Some Tertiary Brachiopods of the East Coast of the United States. Smithsonian Contributions to Paleobiology, Number 64. Ehlers, G.M. (1963). Cyrtina hamiltonensis (Hall) and a New Species of this Brachiopod Genus from New York. Contributions from the Museum of Paleontology - The University of Michigan, Vol. XVIII, Number 12. Feldman, H.R. (1985). Brachiopods of the Onondaga Limestone in Central and Southeastern New York.Bulletin of the American Museum of Natural History, Vol.179, Article 3. Greiner, H. (1957). "Spirifer disjunctus": Its Evolution and Paleoecology in the Catskill Delta. Peabody Museum of Natural History, Bulletin 11. Hanken, N.-M., and D.A.T. Harper (1985). The Taxonomy, Shell Structure, and Palaeoecology of the Trimerellid Brachiopod Gasconsia Northrop. Palaeontology, Vol.28, Part 2. Johnson, M.E. (1979). Evolutionary Brachiopod Lineages from the Llandovery Series of Eastern Iowa. Palaeontology, Vol.22, Part 3. Schuchert, C. (1897). A Synopsis of American Fossil Brachiopoda Including Bibliography and Synonymy. Bulletin of the United States Geological Survey, Number 87. (494 pages, 34.5MB download) Von Bitter, P.H. and R. Ludvigsen (1979). Formation and Function of Protegular Pitting in Some North American Acrotretid Brachiopods. Palaeontology, Vol.22, Part 3. General Brachiopoda - South America/Central America/Caribbean Cooper, G.A. (1979). Tertiary and Cretaceous Brachiopods from Cuba and the Caribbean. Smithsonian Contributions to Paleobiology, Number 37. Sandy, M.R. (1997). Mesozoic Brachiopods of Mexico - A Review and Some Comments on Their Paleobiogeographic Affinities and Paleoecology.Revista Mexicana de Ciencias Geologicas, Vol.14, Number 2. General Brachiopoda Ager, D.V. (1957). The True Rhynchonella. Palaeontology, Vol.1, Part 1. Amos, A. and A.J. Boucot (1963). A Revision of the Brachiopod Family Leptocoeliidae. Palaeontology, Vol.6, Part 3. Baker, P.G. (1990). The Classification, Origin and Phylogeny of Thecideidine Brachiopods. Palaeontology, Vol.33, Part 1. Baker, P.G. (1984). New Evidence of a Spiriferide Ancestor for the Thecideidina (Brachiopoda). Palaeontology, Vol.27, Part 4. Biernat, G. and C.C. Emig (1993). Anatomical distinctions of the Mesozoic lingulide brachiopods. Acta Palaeontologica Polonica, 38(1-2). Biernat, G. and A. Williams (1971). Shell Structure of the Siphonotretacean Brachiopoda. Palaeontology, Vol.14, Part 3. Boucot, A.J. and G.M. Ehlers (1963). Two New Genera of Stricklandid Brachiopods. Contributions from the Museum of Paleontology - The University of Michigan, Vol.XVIII, Number 4. Campbell, K.S.W. (1959). The Type Species of Three Upper Palaeozoic Punctate Spiriferoids. Palaeontology, Vol.1, Part 4. Carlson, S.J. (2016). The Evolution of Brachiopoda. Annual Review of Earth and Planetary Sciences, 44(1). Cooper, G.A. (1983). The Terebratulacea (Brachiopoda), Triassic to Recent: A Study of the Brachidia (Loops).Smithsonian Contributions to Paleobiology, Number 50. (460 pages, 21.3 MB) Cowen, R. (1975). 'Flapping valves' in brachiopods. Lethaia, Vol.8. Emig, C.C. (2002). Tools for linguloid taxonomy: the genus Obolus (Brachiopoda) as an example. Notebooks on Geology, Article 2002/01. Fursich, F.T. and J.M. Hurst (1974). Environmental Factors Determining the Distribution of Brachiopods. Palaeontology, Vol.17, Part 4. Harper, D.A.T. and E. Gallagher (2001). Diversity, disparity and distributional patterns amongst the orthide brachiopod groups. Journal of the Czech Geological Society, (46), 3-4. Johnson, J.G. (1974). Affinity of Dayiacean Brachiopods. Palaeontology, Vol.17, Part 2. MacKinnon, D.I. and A. Williams (1974). Shell Structure of Terebratulid Bachiopods. Palaeontology, Vol.17, Part 1. Mergl, M. (2010). Discinid brachiopod life assemblages: Fossil and extant. Bulletin of Geosciences, 85(1). Plotnick, R.E., et al. (2013). The Orientation of Strophomenid Brachiopods on Soft Substrates. Journal of Paleontology, 87(5). Rudwick, M.J.S. (1964). The Function of Zigzag Deflexions in the Commissures of Fossil Brachiopods. Palaeontology, Vol.7, Part 1. Steele-Petrovic, H.M. (1979). The Physiological Differences Between Articulate Brachiopods and Filter-Feeding Bivalves as a Factor in the Evolution of Marine Level-Bottom Communities. Palaeontology, Vol.22, Part 1. Williams, A. (1968). Evolution of the Shell Structure of Articulate Brachiopods. Special Papers in Palaeontology, Number 2. Williams, A. and L.E. Holmer (1992). Ornamentation and Shell Structure of Acrotretoid Brachiopods. Palaeontology, Vol.35, Part 3. Williams, A. and S. Mackay (1979). Differentiation of the Brachiopod Periostracum. Palaeontology, Vol.22, Part 3. Williams, A. and A.D. Wright (1970). Shell Structure of the Craniacea and Other Calcareous Inarticulate Brachiopoda. Special Papers in Palaeontology, Number 7. Williams, A. and A.D. Wright (1961). The Origin of the Loop in Articulate Brachiopods. Palaeontology, Vol.4, Part 2. Williams, A., et al. (1998). The Diversity and Phylogeny of Paterinate Brachiopods. Palaeontology, Vol.41, Part 2. Wright, A.D. (1981). The External Surface of Dictyonella and of Other Pitted Brachiopods. Palaeontology, Vol.24, Part 3. Wright, A.D. (1971). Taxonomic Significance of the Pseudodeltidium in Triplesiacean Brachiopods. Palaeontology, Vol.14, Part 2. Wright, A.D. (1963). The Morphology of the Brachiopod Superfamily Triplesiacea. Palaeontology, Vol.5, Part 4. Wright, A.D. and M. Melou (1998). Mantle-Body Arrangement Along the Hinge of Early Protrematous Brachiopods: Evidence from Crozonorthis. Palaeontology, Vol.41, Part 4. Wright, A.D. and J. Nolvak (1997). Functional Significance of the Spines of the Ordovician Lingulate Brachiopod Acanthambonia. Palaeontology, Vol.40, Part 1. Wright, A.D. and M. Rubel (1996). A Review of the Morphological Features Affecting the Classification of Clitambonitidine Brachiopods. Palaeontology, Vol.39, Part 1.
  17. cyrtoceras erratics

    title is self-explanatory you might want to read it,because a)it's by Dzik b)thus very good Some of the references can be gotten through BHL,btw http://www.paleo.pan.pl/people/Dzik/Publications/Dzik_Kisselev 1995.pdf http://cdn.palass.org/publications/palaeontology/volume_33/pdf/vol33_part3_pp623-630.pdf
  18. bactroceras (eobactrites)nautiloid

    I haven't checked with Fruitbat's Library yet,so this might be in there as well. anyway https://www.researchgate.net/publication/274782793_A_revision_of_the_Ordovician_cephalopod_Bactrites_sandbergeri_Barrande_Systematic_position_and_palaeobiogeography_of_Bactroceras
  19. Castoroides

    http://www.researchgate.net/publication/268035498_Taxonomy_of_the_Pleistocene_giant_beaver_Castoroides_(Rodentia_Castoridae)_from_the_southeastern_United_States
  20. Questions About Pholadomya Genus

    What would the following be for a general fossil found in the Pholadomya genus? Modes of life: Taxonomy: Fossil Range: Anatomical Features: Nicknames:
  21. The End Of Reptiles?

    Trouble in classification may require getting rid of Reptilia... http://phys.org/news/2014-10-reptiles.html
  22. The following text is largely a translation of an article I wrote for the Nederlandse Varenvereniging (Dutch Fern Society) in 2010, for a special issue on fossil ferns. I updated the text where needed and made a few expansions/changes. Unfortunately, I had to leave out quite some of the figures of the original text. Hopefully though, some TFF members may still find the text useful, and perhaps even entertaining. Taxonomy (derived from the Greek terms “taxis” and “nomina”, translating into “arrangement method”) is the science which deals with the study of identifying, grouping, and naming organisms according to their established natural relationship. For plants, the onset of taxonomy is marked by Linnaeus’ work Species Plantarum, published in 1753, which introduced the concepts of their biological classification and contains the first scientific plant names nowadays considered to be validly published [stace, 1991]. In theory, the basic principles as laid out by Linnaeus are (and should be!) the same for both extant and fossil (extinct) plants. In practice however, there are some notable and inevitable differences. DNA analysis for example, becoming more and more important in the taxonomy of extant organisms, usually cannot be applied to fossils. Below, we will briefly discuss the methodology adopted by palaeobotanists to overcome these practical hurdles and classify plant fossils. Palaeobotanical nomenclature While fragments of leaves, branches, bark, reproductive organs and parts of the rooting system are rather common finds, fossil remains of larger parts, or of the plants as a whole, are extremely rare to non-existent. To cope with this, the nomenclature used in the classification of plant fossils is somewhat different from that used by botanists for extant plants, and this can cause some confusion. Within the regular Linnaean system of botanical nomenclature, each plant –as a whole– is given one single name, consisting of a genus- and species name. Higher hierarchical taxa (such as family, order and class) indicate the more distant relations between species. Palaeobotanists use similar binomial names, but assign separate systematic names to the different parts of plants, such as foliage and roots, thereby enabling the classification of small fossil fragments. A single plant can easily give rise to five or six fossil genera this way [Cleal and Thomas, 1994, p. 46]. Fossil taxa The lycophytes, distant relatives of the extant shrub Lycopodium, form a nice example. During Carboniferous times, these plants formed a major element of the swamp floras. Some of the plants could attain heights well over 30 meters [bateman et al., 1992], and finding the fossil remains of a complete specimen is therefore virtually impossible. This difficulty is reflected in lycophyte systematics in a number of ways. Stigmaria (text-fig. 1) for example, represents the roots of several types of lycopods, such as Lepidodendron and Sigillaria. Grouping the roots together in one genus is the only workable solution, as they are found almost exclusively disconnected from the subaerial parts of the plants. From a biological perspective, further separation would be desirable, of course. However, we cannot make the distinction on basis of the limited fossil evidence. This limitation has significant consequences though. Now, we can't include Stigmaria in the Lepidodendraceae, nor can we group it into the Sigillariaceae; the fossil genus has limited biological meaning. There is also no such thing as a ‘Stigmaria plant’, bearing Stigmaria leaves and Stigmaria branches. These and the other distinct structures, such as the reproductive organs, are assigned their own generic names. Text-figure 1: Stigmaria, the roots of several types of lycophytes, but not a complete plant Morphotaxa Identification problems commonly arise when having to distinguish between true ferns and a group of early gymnosperms, informally known as the pteridosperms. I would like to ask you to take a close look at text-figure 2 now, for the proof of the pudding is in the eating. Without consulting the caption: how many and which ones of these fossil fragments represent true ferns? Text-figure 2: caption with answers can be found at the end of this post The way the question is formulated probably raises a suspicion that pteridosperms are among these fragments. Indeed, there are. However, in the beginning of the nineteenth century (the early days of palaeobotany as a science) all these fossils would probably have been classified as ferns. This is not that strange, really, as the compound leaves –at least superficially– show great resemblance. As a matter of fact, their fronds are so similar that the pteridosperms are also known as “seed ferns”. This is a rather misleading name, since pteridosperm biology is quite different from that of the ferns; they bore seeds and are more closely related to the cycads [Cleal and Thomas, 2009, p. 138]. Started to wonder how well you did as a palaeobotanist? The caption (can be found at the end of this post) lists which of the specimens are ferns and which are pteridosperms. Fern- and pteridosperm fronds can be distinguished from one another with certainty only after a fossil specimen bearing either sporangia or seeds (ovules) has been found. The third fragment (text-fig. 2) shows an example from the Middle Triassic of Australia, where the frond on the right-hand side of the photo bears sporangia [see also Holmes, 2001]. However, the great majority of fossil specimens consists of sterile fronds, lacking such diagnostic features. Again, palaeobotanists turn to the usage of an artificial classification scheme, namely that of morphotaxa [e.g. Brongniart, 1822]. This system is based on the shape of the pinnules and the larger scale architecture of the fronds. It is thus based solely on the morphology of the fossil, and not on biological affinity. As a consequence, morphogenera act like “collector bins” for species that cannot be assigned to proper fossil genera and thereby generally contain several types of plants. Foliage belonging to the morphogenus Pecopteris, for instance, was not only borne by several Filicales and Marattiales ferns (among which the Carboniferous tree-fern Psaronius), but also by at least one pteridosperm [Taylor et al., 2009, p. 680]. In this regard morphogenera differ from fossil genera, such as Lepidodendron and Stigmaria. The latter names immediately tell us that we’re dealing with lycophytes. As soon as sufficient evidence to do so becomes available –such as in the rare case a fertile frond or one with attached seeds is found– the species is placed in a more natural, fossil genus. Scolecopteris, for example, represents species with a pecopterid (Pecopteris-like) appearance that have a known marattialean affinity. This could be discerned through exceptionally well preserved fossils (so-called “coal balls”), in which the sporangia can be studied in detail [e.g. Ewart, 1961]. Note that such finds only provide evidence for the specific species concerned in the attachment and do not generalize to the form-genera to which they belong. Morphogenera are not completely abandoned, even when the biological affinity is known, for it is convenient to keep them as a synonymy [Chaloner, 1986]. Usage of a full name like Asterotheca (al. Pecopteris) arborescens (Schlotheim) Kidston, 1924, for instance, makes it immediately clear that this frond has a pecopterid morphology. Effect of taphonomy Taphonomy is a common source of bias in the fossil record and may also become important for the identification of single specimens, hence a short note here. For a more extensive discussion on taphonomy and its effects the reader is referred to the CarboBase page on the subject and the references given there. Taphonomy is a collective term for all the processes that affect plant remains as they go from the biosphere to the lithosphere. A fossil may, for example, have been transported, abraded, decayed or partially eaten before becoming buried in the sediment and onset of fossilization. As a consequence, there is considerable variation in the degree of preservation between fossils; some specimens can show signs of significant rot before conservation. This is again nicely illustrated by the lycophytes, as the lowermost stem portions of Sigillaria trees often experienced significant decortication prior to burial and fossilization. Compared to regular Sigillaria specimens, the resulting bark fossils –referred to as Syringodendron– lack leaf cushions, but instead only display pairs of markings. It should be noted that, used in this manner, the name Syringodendron represents no taxonomically independent genus, but only a (morphologically distinct) decortication state of another. Similarly, Knorria represents bark of the Lepidodendron-type that underwent some degree of rotting before fossilization. Post-burial alteration can also be important, as fossils occur in many forms of preservation (compressions, permineralisations, etc.), depending on the conditions prevailing during fossilization and diagenesis. Each of these preservation modes can provide different types of information. However, this variation can considerably complicate taxonomy, as palaeobotanists will always have to decide whether the differences they observe between any two fossils are truly biologic or, alternatively, due to another type of fossilization. Sometimes this gives rise to the usage of different fossil genus and species names for what might very well be the same plant. The fossil genera Calamites and Arthropitys represent, respectively, the compressions and anatomically preserved fossils of calamite stems, for example. Complete plant reconstructions One of the most challenging aspects of palaeobotany is trying to reconstruct what the whole plant would have looked like. These reconstructions are of key importance, because analytical methods used in systematic biology to determine the evolutionary relations between organisms (such as cladistics) do not work well on separate organs [Cleal and Thomas, 2009, p. 46]. Reconstruction of the whole plant requires us to group together the fossils we treated and named as separate entities until now. In the reconstruction of the giant horsetail-tree Calamites (text-fig. 3), for example, Calamites (stems), Annularia (foliage), Calamostachys (cones), and Pinnularia (rootlets) are associated with each other. Text-figure 3: Reconstructions of the Calamites-tree. Schematics modified from Taylor et al. (2009) and Langford Producing such a complete plant reconstruction is comparable to assembling a complex jigsaw puzzle. Or, actually, more like building a couple of these puzzles simultaneously, as generally different kinds of plants have fossilized together. Also, important pieces of the puzzle might still be missing (you don’t know how many) and, moreover, there is no box with example picture to work with. Furthermore, convergent or divergent evolution may have resulted in multiple plants with, for example, similar foliage but different reproductive organs [Cleal and Thomas, 1994, p. 46], as was shown earlier to be the case for ferns and pteridosperms (text-fig. 2). It is not surprising we sometimes have to make assumptions due to the difficulties outlined above. As a consequence, whole plant reconstructions are always, at least to some extent, hypothetical. This is also the case for Tempskya, a genus of “false trunk” tree ferns, known principally from silicified trunks from the Cretaceous. The characteristics of the petioles and petiole traces on these fossils suggest Tempskya bore small-sized, abundant foliage along the length of its trunk instead of a crown of fronds [Taylor et al., 2009, p. 458]. The reconstruction of Tempskya incorporates this evidence. However, fossils of the fronds themselves have never been found [stewart en Rothwell, 2009, p. 257; Taylor et al., 2009, p. 458] and their appearance in the reconstruction is therefore open for interpretation of the artist. It is very well possible whole plant reconstructions need to be modified when more fossil evidence becomes available. As a consequence the literature generally contains multiple reconstruction proposals for the same plant group [e.g. Pfefferkorn et al., 1984, p. 3]. Therefore, it is important we appreciate these complete plant reconstructions for what they are: not taxonomic species, but working-hypotheses, based on the best data available at the time. Notes on scientific names As already briefly mentioned in the section on palaeobotanical nomenclature, plant fossils (and extant plants alike) are assigned a name, consisting of a genus- and species name. This paragraph provides some further general notes on scientific names. It is customary to write these names in italics, where only the genus name gets a capital letter. The complete record should also contain the name of the author who first described the species, together with the year of publication of this description: e.g.: Calamites suckowii Brongniart, 1828 The species in the example above belongs to the genus Calamites, and was first described by Brongniart in the year 1828. When subsequent changes are made to the classification of a species, this should be included in the scientific name in certain cases. When the species is transferred to a different or amended genus, for example, the first, original author is only mentioned between brackets, followed by the author who published the amended diagnosis and the year of publication of this change: e.g.: Alethopteris serlii (Brongniart) Göppert, 1836 In 1828, Brongniart originally published the species of the example above as Pecopteris serlii. Subsequent work in 1836 by Göppert led to the transfer of this species to another genus, namely Alethopteris (a genus name coined by Sternberg in 1826). Sometimes it is very difficult to classify a fossil with certainty. In such cases, taxonomists make use of so-called “open nomenclature” [bengtson, 1988]. The following three abbreviations are used most frequently when the classification is uncertain. When “aff.” precedes the species name this indicates that the specimen is considered to be a possible new species, closely related to the mentioned species. The material is insufficient for the formal formulation of a new species though (used mainly in the literature). When “cf.” precedes the species name this indicates that the determination is uncertain. This may be due to poor preservation of the fossil. Sometimes “?” is also used for this purpose. In the example below, the fossil specimen probably belongs to the species Calamites suckowii, but some characteristics could not be discerned due to poor preservation. e.g.: Calamites cf. suckowii Brongniart, 1828 When “sp.” is written after a genus name this indicates that the specimen couldn’t be related to any established species. e.g.: Calamites sp. In this example, the fossil specimen is considered to belong to the genus Calamites, but the species couldn’t be determined (or no further classification attempt has been made yet). Note the caption of text-figure 3 contains open nomenclature. Caption text-figure 2: Several fossils of ferns and pteridosperms. Pteridosperms: A, B, C, D, E and I. Ferns: C, F, G and H. How many did you get right? For the enthusiasts: A = Mariopteris cf. muricata, B = Alethopteris davreuxii, C = Asterotheca chevronervia, D = Eusphenopteris striata, E = Alethopteris serlii, F = Pecopteris sp., G = Pecopteris polymorpha, H = Renaultia crepinii, I = Callipteridium gigas.
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