Project 2116: J. C. Lamsdell, D. E. G. Briggs, H. P. Liu, B. J. Witzke, R. M. McKay. 2015. The oldest described eurypterid: a giant Middle Ordovician (Darriwilian) megalograptid from the Winneshiek Lagerstätte of Iowa. BMC Evolutionary Biology. 15 (169):1–31.
Specimen: Pentecopterus decorahensis (unvouchered)

Abstract

Background: Eurypterids are a diverse group of chelicerates known from ~250 species with a sparse Ordovician record currently comprising 11 species; the oldest fully documented example is from the Sandbian of Avalonia. The Middle Ordovician (Darriwilian) fauna of the Winneshiek Lagerstätte includes a new eurypterid species represented by more than 150 specimens, including some juveniles, preserved as carbonaceous cuticular remains. This taxon represents the oldest described eurypterid, extending the documented range of the group back some 9 million years.
Results: The new eurypterid species is described as Pentecopterus decorahensis gen. et sp. nov.. Phylogenetic analysis places Pentecopterus at the base of the Megalograptidae, united with the two genera previously assigned to this family by the shared possession of two or more pairs of spines per podomere on prosomal appendage IV, a reduction of all spines except the pair on the penultimate podomere of appendage V, and an ornamentation of guttalate scales, including angular scales along the posterior margin of the dorsal tergites and in longitudinal rows along the tergites. The morphology of Pentecopterus reveals that the Megalograptidae are representatives of the derived carcinosomatoid clade and not basal eurypterids as previously interpreted.
Conclusions: The relatively derived position of megalograptids within the eurypterids indicates that most eurypterid clades were present by the Middle Ordovician. Eurypterids either underwent an explosive radiation soon after their origination, or earlier representatives, perhaps Cambrian in age, remain to be discovered. The available instars of Pentecopterus decorahensis suggest that eurypterids underwent extreme appendage differentiation during development, a potentially unique condition among chelicerates. The high degree of appendage specialization in eurypterids is only matched by arachnids within chelicerates, supporting a sister taxon relationship between them.


Read the article »

Article DOI: 10.1186/s12862-015-0443-9

Project DOI: 10.7934/P2116, http://dx.doi.org/10.7934/P2116
This project containsMatrices
  • 1 Media
  • 1 Matrix
  • 74 Taxa
  • 1 Specimen
  • 158 Characters
Total size of project's media files: 1 MB

Download Project SDD File
Total scored cells: 8453
Total media associated with cells: 0
Total labels associated with cell media: 0
Characters
Total characters: 158
Total characters with associated media: 0
Total characters with media with labels: 0
Total character states: 366
Total character states with associated media: 0
Total character states with media with labels:0
Total unordered/ordered characters:158/0
Currently Viewing:
MorphoBank Project 2116

    This research
    supported by

    Authors' Institutions

    • West Virginia University



    Members

    member name taxa specimens media chars character
    media
    labels
    cell scorings
    (scored, NPA, "-")
    cell
    medialabels
    rules
    James Lamsdell
    Project Administrator
    Last logged in 09/03/15
    7411158008453
    (7751, 0, 702)
    000


    Taxonomic Overview for Matrix 'M23227' (74 Taxa)

    taxon unscored
    cells
    scored
    cells
    no cell
    support
    NPA
    cells
    "-" cellscell images labels on
    cell images
    member
    access
    [1] Weinbergina opitzi
    Last Modified in 02/10/15
    8116116034001
    [2] Chasmataspis laurencii
    Last Modified in 02/10/15
    568686016001
    [3] Octoberaspis ushakovi
    Last Modified in 02/10/15
    35109109014001
    [4] Diploaspis casteri
    Last Modified in 02/10/15
    519494013001
    [5] Loganamaraspis dunlopi
    Last Modified in 02/10/15
    598484015001
    [6] Brachyopterus stubblefieldi
    Last Modified in 02/10/15
    35108108015001
    [7] Alkenopterus burglahrenisis
    Last Modified in 02/10/15
    63909005001
    [8] Rhenopterus diensti
    Last Modified in 02/10/15
    4135135019001
    [9] Parastylonurus ornatus
    Last Modified in 02/10/15
    4138138016001
    [10] Laurieipterus elegans
    Last Modified in 02/10/15
    62878709001
    [11] Kokomopterus longicaudatus
    Last Modified in 02/10/15
    27118118013001
    [12] Hardieopterus macrophthalmus
    Last Modified in 02/10/15
    34110110014001
    [13] Drepanopterus pentlandicus
    Last Modified in 02/10/15
    3141140015001
    [14] Hibbertopterus scouleri
    Last Modified in 02/10/15
    21124123014001
    [15] Megarachne servinei
    Last Modified in 02/10/15
    107484704001
    [16] Stoermeropterus conicus
    Last Modified in 02/10/15
    0147146012001
    [17] Stoermeropterus latus
    Last Modified in 02/10/15
    36111111011001
    [18] Stoermeropterus nodosus
    Last Modified in 02/10/15
    67868605001
    [19] Vinetopterus struvei
    Last Modified in 02/10/15
    16130130012001
    [20] Vinetopterus martini
    Last Modified in 02/10/15
    4610310309001
    [21] Moselopterus ancylotelson
    Last Modified in 02/10/15
    1142142015001
    [22] Onychopterella augusti
    Last Modified in 02/10/15
    4810310307001
    [23] Onychopterella kokomoensis
    Last Modified in 02/10/15
    10138138010001
    [24] Dolichopterus macrocheirus
    Last Modified in 02/10/15
    214814808001
    [25] Eurypterus remipes
    Last Modified in 02/10/15
    014914909001
    [26] Hughmilleria socialis
    Last Modified in 02/10/15
    2145145011001
    [27] Tylopterella boylei
    Last Modified in 02/10/15
    86676705001
    [28] Echinognathus clevelandi
    Last Modified in 02/10/15
    129292900001
    [29] Megalograptus williamsae
    Last Modified in 02/10/15
    144141400001
    [30] Megalograptus welchi
    Last Modified in 02/10/15
    137212100001
    [31] Megalograptus ohioensis
    Last Modified in 02/10/15
    0145145013001
    [32] Pentecopterus decorahensis
    Last Modified in 03/23/15
    54979707001
    [33] Holmipterus suecicus
    Last Modified in 02/10/15
    97585803001
    [34] Lanarkopterus dolichoschelus
    Last Modified in 02/10/15
    914214207001
    [35] Mixopterus kiaeri
    Last Modified in 02/10/15
    614314309001
    [36] Mixopterus multispinosus
    Last Modified in 02/10/15
    2412712707001
    [37] Strobilopterus laticeps
    Last Modified in 02/10/15
    91646403001
    [38] Strobilopterus princetonii
    Last Modified in 02/10/15
    2512712706001
    [39] Strobilopterus proteus
    Last Modified in 02/10/15
    1214214204001
    [40] Buffalopterus pustulosus
    Last Modified in 02/10/15
    68838307001
    [41] Strobilopterus richardsoni
    Last Modified in 02/10/15
    103535302001
    [42] Erieopterus microphthalmus
    Last Modified in 02/10/15
    4143143011001
    [43] Paraeurypterus anatoliensis
    Last Modified in 02/10/15
    89676702001
    [44] Pentlandopterus minor
    Last Modified in 02/10/15
    78757505001
    [45] Dolichopterus jewetti
    Last Modified in 02/10/15
    714314308001
    [46] Ruedemannipterus stylonuroides
    Last Modified in 02/10/15
    93636302001
    [47] Clarkeipterus testudineus
    Last Modified in 02/10/15
    107494902001
    [48] Clarkeipterus otisius
    Last Modified in 02/10/15
    131262601001
    [49] Erieopterus eriensis
    Last Modified in 02/10/15
    3511811805001
    [50] Eurypterus henkeni
    Last Modified in 02/10/15
    2712612605001
    [51] Eurypterus tetragonophthalmus
    Last Modified in 02/10/15
    014914909001
    [52] Eurypterus leopoldi
    Last Modified in 02/10/15
    77787803001
    [53] Eurypterus pittsfordensis
    Last Modified in 02/10/15
    1713513506001
    [54] Eurypterus henningsmoeni
    Last Modified in 02/10/15
    3711611605001
    [55] Orcanopterus manitoulinensis
    Last Modified in 02/10/15
    25123123010001
    [56] Pterygotus anglicus
    Last Modified in 02/10/15
    2134134022001
    [57] Adelophthalmus sievertsi
    Last Modified in 02/10/15
    1136136021001
    [58] Eurypterus dekayi
    Last Modified in 02/10/15
    314714708001
    [59] Carcinosoma newlini
    Last Modified in 02/10/15
    8140140010001
    [60] Carcinosoma libertyi
    Last Modified in 02/10/15
    60929206001
    [61] Rhinocarcinosoma vaningeni
    Last Modified in 02/10/15
    63929203001
    [62] Eusarcana acrocephala
    Last Modified in 02/10/15
    78737307001
    [63] Eusarcana scorpionis
    Last Modified in 02/10/15
    8138138012001
    [64] Slimonia acuminata
    Last Modified in 02/10/15
    5140140013001
    [65] Acutiramus bohemicus
    Last Modified in 02/10/15
    915353014001
    [66] Acutiramus macrophthalmus
    Last Modified in 02/10/15
    3133133022001
    [67] Erettopterus bilobus
    Last Modified in 02/10/15
    5133133020001
    [68] Erettopterus osiliensis
    Last Modified in 02/10/15
    15123123020001
    [69] Erettopterus serricaudatus
    Last Modified in 02/10/15
    125313102001
    [70] Erettopterus waylandsmithi
    Last Modified in 02/10/15
    113393906001
    [71] Jaekelopterus rhenaniae
    Last Modified in 02/10/15
    27109109022001
    [72] Jaekelopterus howelli
    Last Modified in 02/10/15
    87656506001
    [73] Ciurcopterus ventricosus
    Last Modified in 02/10/15
    34114114010001
    [74] Nanahughmilleria norvegica
    Last Modified in 02/10/15
    614614606001


    Project views

    type number of views Individual items viewed (where applicable)
    Total project views17866
    Project overview3050
    Media views2793Media search (2419 views); M395245 (374 views);
    Matrix views1553Matrix landing page (1319 views); Winneshiek Eurypterid Analysis (234 views);
    Bibliography597
    Specimen list1290
    Taxon list8583




    Project downloads

    type number of downloads Individual items downloaded (where applicable)
    Total downloads from project195
    Project downloads183
    Matrix downloads12Winneshiek Eurypterid Analysis (12 downloads);