Trilobite Legs & Soft Parts

NOTE: For many of these references, I have pdfs. This list includes all known papers on the structure of fossil trilobite legs and soft parts. If you think I am missing something, please let me know!

Trilobite legs and soft parts (144)

1.     Babcock, L. E. & Peel, J. S. (2007). Palaeobiology, taphonomy and stratigraphic significance of the trilobite Buenellus from the Sirius Passet Biota, Cambrian of North Greenland. Memoirs of the Association of Australasian Palaeontologists 34, 401–418.

2.     Beecher, C. E. (1893). On the thoracic legs of Triarthrus. American Journal of Science 467–470.

3.     Beecher, C. E. (1894). The appendages of the pygidium of Triarthrus. American Journal of Science 47, 298–300.

4.     Beecher, C. E. (1895). Further observations on the ventral structure of Triarthrus. The American Geologist 15, 91–100.

5.     Beecher, C. E. (1895). Structure and appendages of Trinucleus. American Journal of Science 307–311.

6.     Beecher, C. E. (1896). On a supposed discovery of the antennae of trilobites by Linnaeus in 1759. The American Geologist 17, 303–306.

7.     Beecher, C. E. (1902). The ventral integument of trilobites. American Journal of Science 13, 165–174.

8.     Bergström, J. (1969). Remarks on the appendages of trilobites. Lethaia 2, 395–414.

9.     Bergström, J. (1972). Appendage morphology of the trilobite Cryptolithus and its implications. Lethaia 5, 85–94.

10.  Bergström, J. & Brassel, G. (1984). Legs in the trilobite Rhenops from the Lower Devonian Hunsrück Slate. Lethaia 17, 67–72.

11.  Bernard, H. M. (1893). Trilobites with antennae at last! Nature 48, 582–583.

12.  Bicknell, R. D. C., Holmes, J. D., Edgecombe, G. D., Losso, S. R., Ortega-Hernández, J., Wroe, S. & Paterson, J. R. (2021). Biomechanical analyses of Cambrian euarthropod limbs reveal their effectiveness in mastication and durophagy. Proceedings of the Royal Society B 288, 20202075.

13.  Billings, E. (1870). Notes on some specimens of Lower Silurian trilobites. Quarterly Journal of the Geological Society of London 26, 479–486.

14.  Braiden, A. K., Whiteley, T. E., Orr, P. J., Siveter, D. J., Siveter, D. J. & Sutton, M. D. (2004). Virtual reconstruction of three-dimensionally preserved trilobites from the Middle Ordovician Rust formation of New York State. Irish Journal of Earth Sciences 22, 57.

15.  Briggs, D. E. G., Bottrell, S. H. & Raiswell, R. (1991). Pyritization of soft-bodied fossils: Beecher’s Trilobite Bed, Upper Ordovician, New York State. Geology 19, 1221–1224.

16.  Briggs, D. E. G. & Edgecombe, G. D. (1993). Beecher’s Trilobite Bed. Geology Today 9, 97–102.

17.  Briggs, D. E. G., Lieberman, B. S., Hendricks, J. R., Halgedahl, S. L. & Jarrard, R. D. (2008). Middle Cambrian arthropods from Utah. Journal of Paleontology 82, 238–254.

18.  Budil, P. & Fatka, O. (2022). Ordovician trilobites with soft parts in African West Gondwana, European peri-Gondwana and Avalonia: a review. Geological Society, London, Special Publications 485, 139–152.

19.  Calman, W. T. (1919). Dr. Walcott’s researches on the appendages of trilobites. Geological Magazine 6, 359–363.

20.  Campbell, K. S. W. (1975). The functional anatomy of phacopid trilobites: musculature and eyes. Journal and Proceedings, Royal Society of New South Wales 108, 168–188.

21.  Chapman, F. (1912). Reports on fossils.—Middle Devonian of the Buchan District. Records of the Geological Survey of Victoria 3, 218–223.

22.  Chatterton, B. D. E., Johanson, Z. & Sutherland, G. (1994). Form of the trilobite digestive system: alimentary structures in Pterocephalia. Journal of Paleontology 68, 294–305.

23.  Chen, F., Zhang, Z., Betts, M. J., Zhang, Z. & Liu, F. (2019). First report on Guanshan Biota (Cambrian Stage 4) at the stratotype area of Wulongqing Formation in Malong County, Eastern Yunnan, China. Geoscience Frontiers 10, 1459–1476.

24.  Cisne, J. L. (1975). Anatomy of Triarthrus and the relationships of the Trilobita. Fossils and Strata 4, 45–63.

25.  Cisne, J. L. (1981). Triarthrus eatoni (Trilobita): Anatomy of its exoskeletal, skeletomuscular, and digestive systems. Palaeontographica Americana 9, 95–142.

26.  Corbacho, J., López-Soriano, F. J., Morrison, S. & Hammond, K. (2023). Digestive system in Basilicus calzadai Corbacho, 2011 (Trilobita) from the Upper Ordovician of Bou Nemrou — El Kaid Errami, Morocco. Batalleria 29, 24–31.

27.  Dana, J. D. (1871). On the supposed legs of the trilobite, Asaphus platycephalus. American Journal of Science and Arts, third series 1, 320–332.

28.  Dana, J. D. (1871). On the supposed legs of the trilobite, Asaphus platycephalus. Nature 4, 152.

29.  Dana, J. D. (1872). On the supposed legs of the trilobite, Asaphus platycephalus. The Canadian Naturalist and Quarterly Journal of Science, New Series 6, 348–350.

30.  Dana, J. D. (1872). Supposed legs of trilobites. American Journal of Science 3, 221–222.

31.  Du, K.-S., Guo, J., Losso, S. R., Pates, S., Li, M. & Chen, A.-L. (2024). Multiple origins of dorsal ecdysial sutures in trilobites and their relatives. Elife 12, RP93113.

32.  Dunbar, C. O. (1925). Antennae in Olenellus getzi n. sp. American Journal of Science 5, 303–308.

33.  Edgecombe, G. D. & Fortey, R. A. (2023). A novel antennal form in trilobites. Journal of Paleontology 97, 152–157.

34.  El Albani, A., Mazurier, A., Edgecombe, G. D., Azizi, A., El Bakhouch, A., Berks, H. O., Bouougri, E. H., Chraiki, I., Donoghue, P. C. J., Fontaine, C., Gaines, R. R., Ghnahalla, M., Meunier, A., Trentesaux, A. & Paterson, J. R. (2024). Rapid volcanic ash entombment reveals the 3D anatomy of Cambrian trilobites. Science 384, 1429–1435.

35.  Eldredge, N. (1971). Patterns of cephalic musculature in the Phacopina (Trilobita) and their phylogenetic significance. Journal of Paleontology 45, 52–67.

36.  English, A. M., Babcock, L. E., Mignery, B. & Kiel, B. A. (2006). Feeding behavior of two Cincinnatian (Ordovician) trilobites inferred from trace fossils and nonmineralized anatomy. Abstracts with Programs - Geological Society of America 38, 12.

37.  English, A. M. & Babcock, L. E. (2007). Feeding behaviour in two Ordovician trilobites inferred from trace fossils and non-biomineralized anatomy, Ohio and Kentucky, USA. Memoirs of the Association of Australasian Palaeontologists 34, 537–544.

38.  Eriksson, M. E. & Terfelt, F. (2012). Exceptionally preserved Cambrian trilobite digestive system revealed in 3D by synchrotron-radiation X-ray tomographic microscopy. PLoS One 7, e35625.

39.  Eriksson, M. E. & Horn, E. (2017). Agnostus pisiformis — a half a billion-year old pea-shaped enigma. Earth-Science Reviews 173, 65–76.

40.  Farrell, Ú. & Briggs, D. E. G. (2008). Pyritized trilobite faunas from the Ordovician of New York State: Beecher’s Trilobite Bed and the Whetstone Gulf Formation near Lowville. Cuadernos del Museo Geominero, n°9 Advances in Trilobite Research, 109–112.

41.  Fatka, O., Lerosey-Aubril, R., Budil, P. & Rak, Š. (2012). Fossilised guts in trilobites from the Upper Ordovician Letná Formation (Prague Basin, Czech Republic). Bulletin of Geosciences 88, 95–104.

42.  Fatka, O., Budil, P. & David, M. (2015). Digestive structures in Ordovician trilobites Colpocoryphe and Flexicalymene from the Barrandian area of Czech Republic. Estonian Journal of Earth Sciences 64, 255–266.

43.  Fatka, O. & Budil, P. (2018). Digestive structures in Middle Ordovician trilobite Prionocheilus Rouault 1847, from the Barrandian area of Czech Republic. Geologica Acta 16, 65–73.

44.  Fatka, O. (2021). Frontal auxiliary impressions in the Ordovician trilobite Dalmanitina Reed, 1905 from the Barrandian area, Czech Republic. Bulletin of Geosciences 481–491.

45.  Garstang, W. (1940). Størmer on the appendages of trilobites. Annals and Magazine of Natural History 6, 59–66.

46.  Geyer, G. & Landing, E. (2021). The Souss lagerstätte of the Anti-Atlas, Morocco: discovery of the first Cambrian fossil lagerstätte from Africa. Scientific Reports 11, 3107.

47.  Grasshoff, M. (1981). Arthropodisierung als biomechanischer Prozeß und die Entstehung der Trilobiten-Konstruktion [Arthropodization as a biomechanical process and the emergence of trilobite construction]. Paläontologische Zeitschrift 55, 219–235.

48.  Gutiérrez-Marco, J. C., García-Bellido, D. C., Rábano, I. & Sá, A. A. (2017). Digestive and appendicular soft-parts, with behavioural implications, in a large Ordovician trilobite from the Fezouata Lagerstätte, Morocco. Scientific Reports 7, 39728.

49.  Gutiérrez-Marco, J. C., van Roy, P., Lefebvre, B., Zamora, S., Pereira, S. & Rábano, I. (2020). Le Tafilalt Biota: des animaux au corps mou dans des sables de l’Ordovicien supérieur du Maroc. Géochronique 153, 45–51.

50.  Gutiérrez-Marco, J. C., Rábano, I., Sá, A. A., Poblador, J. A. & García-Bellido, D. C. (2022). Nuevo trilobites asáfido con conservación de apéndices en la Biota de Fezouata (Ordovícico Inferior de Marruecos) [New asaphid trilobites with preserved appendages from the Fezouata Biota (Lower Ordovician of Morocco]. Geogaceta 71, 11–14.

51.  Gutiérrez-Marco, J. C., Pereira, S., García-Bellido, D. C. & Rábano, I. (2022). Ordovician trilobites from the Tafilalt Lagerstätte: new data and reappraisal of the Bou Nemrou assemblage. Geological Society, London, Special Publications 485, 97–137.

52.  Hansen, H. J. (1925). On the comparative morphology of the appendages in the Arthropoda. A. Crustacea. Studies on Arthropoda 2, 1–176.

53.  Harper, D. A. T., Hammarlund, E. U., Topper, T. P., Nielsen, A. T., Rasmussen, J. A., Park, T.-Y. S. & Smith, M. P. (2019). The Sirius Passet Lagerstätte of North Greenland: A remote window on the Cambrian Explosion. Journal of the Geological Society 176, 1023–1037.

54.  Haug, C. & Haug, J. T. (2016). New insights into the appendage morphology of the Cambrian trilobite-like arthropod Naraoia compacta. Bulletin of Geosciences 91, 221–227.

55.  Holmes, J. D., Paterson, J. R. & García-Bellido, D. C. (2020). The trilobite Redlichia from the lower Cambrian Emu Bay Shale Konservat-Lagerstätte of South Australia: systematics, ontogeny and soft-part anatomy. Journal of Systematic Palaeontology 18, 295–334.

56.  Hopkins, M. J., Chen, F., Hu, S. & Zhang, Z. (2017). The oldest known digestive system consisting of both paired digestive glands and a crop from exceptionally preserved trilobites of the Guanshan Biota (Early Cambrian, China). PLoS One 12, e0184982.

57.  Hou, J.-B., Hughes, N. C. & Hopkins, M. J. (2023). Gill grooming in middle Cambrian and Late Ordovician trilobites. Geological Magazine 160, 905–910.

58.  Hou, J.-B. & Hopkins, M. J. (2024). New evidence for five cephalic appendages in trilobites and implications for segmentation of the trilobite head. Palaeontology 67, e12723.

59.  Hou, X., Clarkson, E. N. K., Yang, J., Zhang, X., Wu, G. & Yuan, Z. (2008). Appendages of early Cambrian Eoredlichia (Trilobita) from the Chengjiang biota, Yunnan, China. Earth and Environmental Science, Transactions of the Royal Society of Edinburgh 99, 213–223.

60.  Jaekel, O. (1901). Ueber die organisation der trilobiten. Zeitschrift der Deutschen Geologischen Gesellschaft 133–171.

61.  Jaekel, O. (1902). Bemerkungen ueber den Beinbau der Trilobiten [Remarks on the limb structure of trilobites]. Zeitschrift der Deutschen Geologischen Gesellschaft 54, 53–55.

62.  Jell, P. A. (1978). Trilobite respiration and genal caeca. Alcheringa 2, 251–260.

63.  Kemp, J. F. (1893). Some Recently Discovered Trilobites with Appendages. Science 21, 344–345.

64.  Kraft, P., Vaškaninová, V., Mergl, M., Budil, P., Fatka, O. & Ahlberg, P. E. (2023). Uniquely preserved gut contents illuminate trilobite palaeophysiology. Nature

65.  Lamont, A. (1939). Cranidial muscle scars of ‘Ilaenus’ proles var. shelvensis Whittard. Nature 144, 206–208.

66.  Lerosey-Aubril, R., Hegna, T. A. & Olive, S. (2011). Inferring internal anatomy from the trilobite exoskeleton: the relationship between frontal auxiliary impressions and the digestive system. Lethaia 44, 166–184.

67.  Lerosey-Aubril, R., Hegna, T. A., Kier, C., Bonino, E., Habersetzer, J. & Carre, M. (2012). Controls on gut phosphatisation: the trilobites from the Weeks Formation Lagerstätte (Cambrian; Utah). PLoS One 7, e32934.

68.  Lerosey-Aubril, R., Paterson, J. R., Gibb, S. & Chatterton, B. D. E. (2017). Exceptionally-preserved late Cambrian fossils from the McKay Group (British Columbia, Canada) and the evolution of tagmosis in aglaspidid arthropods. Gondwana Research 42, 264–279.

69.  Lerosey-Aubril, R. & Peel, J. S. (2018). Gut evolution in early Cambrian trilobites and the origin of predation on infaunal macroinvertebrates: evidence from muscle scars in. Palaeontology 61, 747–760.

70.  Levy, R. (1971). Noticia sobre el hallazgo de apendices ventrales de trilobites en la Formacion Parcha (Salta) [News about the discovery of ventral appendages of trilobites in the Parcha Formation (Salta)]. Ameghiniana 8, 73–76.

71.  Lin, J.-P. (2007). Preservation of the gastrointestinal system in Olenoides (Trilobita) from the Kaili Biota (Cambrian) of Guizhou, China. Memoirs of the Association of Australasian Palaeontologists 33, 179–189.

72.  Liu, Y., Edgecombe, G. D., Schmidt, M., Bond, A. D., Melzer, R. R., Zhai, D., Mai, H., Zhang, M. & Hou, X. (2021). Exites in Cambrian arthropods and homology of arthropod limb branches. Nature Communications 12, 4619.

73.  Losso, S. R. & Ortega-Hernández, J. (2022). Claspers in the mid-Cambrian Olenoides serratus indicate horseshoe crab–like mating in trilobites. Geology 50, 897–901.

74.  Losso, S. R., Affatato, P., Nanglu, K. & Ortega-Hernández, J. (2023). Convergent evolution of ventral adaptations for enrolment in trilobites and extant euarthropods. Proceedings of the Royal Society B 290, 20232212.

75.  Losso, S. R., Thines, J. E. & Ortega-Hernández, J. (2023). Taphonomy of non-biomineralized trilobite tissues preserved as calcite casts from the Ordovician Walcott-Rust Quarry, USA. Communications Earth & Environment 4, 330.

76.  Losso, S. R. & Ortega-Hernández, J. (2024). Conserved exopodite morphology in three-dimensionally preserved trilobites from the Walcott-Rust Quarry (Mohawkian, Ordovician) of New York, USA. Arthropod Structure & Development 81, 101371.

77.  Losso, S. R. (2024). Morphology, function and taphonomy of Lower Paleozoic trilobites and their close relatives: insights from North American Konservat-Lagerstätten. Ph.D. thesis, Harvard University, Cambridge, MA, 1 pp.

78.  Lü, F.-L., Tan, H.-T., Chen, A.-L., Miao, Z.-X., Wang, S.-T., Zhao, Q. & Du, K.-S. (2022). [A brief introduction to the studies on non-trilobite artiopods in China]. Journal of Yuxi Normal University 38, 32–43.

79.  Matthew, W. D. (1893). On antennae and other appendages of Triarthrus Beckii. American Journal of Science 46, 121–125.

80.  McKenzie, S. (2010). Ordovician trilobite with possible calcified muslces. M.A.P.S. Digest 33, 103–104.

81.  McMenamin, M. A. S. & McMenamin, S. K. (2001). Homeotic Genes, the Antennapedia Complex in the Trilobite Genome, and Iterative Evolution in Nevadiid and Bristoliid Trilobites. In: McMenamin, M. A. S. (ed.) Paleontology Sonora: Lipalian and Cambrian. South Hadley, MA: Meanma Press, 107–113.

82.  Mickleborough, J. (1883). Locomotory appendages of trilobites. Cincinnati Society of Natural History 6, 200–206.

83.  Mickleborough, J. (1884). Locomotory appendages of trilobites. Geological Magazine 80–84, 162.

84.  Moysiuk, J. & Caron, J.-B. (2019). Burgess Shale fossils shed light on the agnostid problem. Proceedings of the Royal Society B 286, 20182314.

85.  Müller, K. J. & Walossek, D. (1987). Morphology, ontogeny, and life habit of Agnostus pisiformis from the Upper Cambrian of Sweden. Fossils and Strata 19, 1–124.

86.  Öpik, A. A. (1959). Genal caeca of agnostids. Nature 183, 1750–1751.

87.  Öpik, A. A. (1961). Alimentary caeca of agnostids and other trilobites. Palaeontology 3, 410–438.

88.  Palmer, D. (1993). Trilobite fossil shows its muscle. New Scientist 140, 20.

89.  Park, T.-Y. S. (2023). Trilobite hypostome as a fusion of anterior sclerite and labrum. Arthropod Structure & Development 77, 101308.

90.  Peel, J. S. (2016). Mineralized gutfills from the Sirius Passet Lagerstätte (Cambrian Series 2) of North Greenland. GFF 139, 83–91.

91.  Pérez-Peris, F., Laibl, L., Vidal, M. & Daley, A. (2021). Systematics, morphology, and appendages of Anacheirurus (Pilekiinae, Trilobita) from the Fezouata Shale and the early diversification of Cheiruridae. Acta Palaeontologica Polonica 66, 857–877.

92.  Ramsköld, L. & Edgecombe, G. D. (1996). Trilobite appendage structure - Eoredlichia reconsidered. Alcheringa 20, 269–276.

93.  Raymond, P. E. (1920). The appendages, anatomy, and relationships of the trilobites. Memoirs of the Connecticut Academy of Arts and Science 7, 1–169.

94.  Raymond, P. E. (1929). A lower Devonian Phacops with ventral appendages. American Journal of Science 17, 280–282.

95.  Robison, R. A. & Babcock, L. E. (2011). Systematics, paleobiology, and taphonomy of some exceptionally preserved trilobites from Cambrian Lagerstätten of Utah. Paleontological Contributions 5, 1–47.

96.  Ross Jr., R. J. (1979). Additional trilobites from the Ordovician of Kentucky. United States Geological Survey Professional Paper 1066D, 1–13.

97.  Rudolph, F. (1992). Kopfmuskulatur bei trilobiten rekonstruktion, funktionsmorphologie und phylogenetisch-systematische schlußfolgerungen. Kiel: Diplom-Arbeit aus dem Zoologischen Institut der Christian-Albrechts-Universität Kiel.

98.  Rudolph, F. (1994). Die Trilobiten der mittelkambrischen Geschiebe. Systematik, Morphologie und Ökologie.

99.  Schmidt, F. (1883). Ob Issledovaniyakh val’kotta, kasatel’no nog i dykhatel’nykh organov trilobitov [On Walcott’s research into the legs and respiratory organs of trilobites]. Trudy Sankt Peterburgskogo Obshchestva Yestestvoispytateley [Proceedings of the St. Petersburg Society of Naturalists] 14, 47–49.

100.                 Schwimmer, D. R. & Montante, W. M. (2007). Exceptional fossil preservation in the Conasauga Formation, Cambrian, Northwestern Georgia, USA. Palaios 22, 360–372.

101.                 Seilacher, A. (1962). Form und Funktion des Trilobiten-Daktylus. Paläontologische Zeitschrift. H. Schmidt-Festband 218–227.

102.                 Shiino, Y., Kuwazuru, O., Suzuki, Y., Ono, S. & Masuda, C. (2014). Pelagic or benthic? Mode of life of the remopleuridid trilobite Hypodicranotus striatulus. Bulletin of Geosciences 89, 207–218.

103.                 Shu, D.-G., Geyer, G. & Zhang, X.-L. (1995). Redlichiacean trilobites with preserved soft-parts from the Lower Cambrian Chengjiang fauna (South China). Beringeria Special Issue 2, 203–241.

104.                 Sinclair, G. W. (1947). Muscle scars in the Ordovician trilobite Illaenus. American Journal of Science 245, 529–536.

105.                 Siveter, D. J., Briggs, D. E. G., Siveter, D. J., Sutton, M. D. & Fortey, R. A. (2008). Horns, eggs and legs: exceptionally preserved new arthropods from the Herefordshire (Silurian) Lagerstätte. In: Rábano, I., Gozalo, R. & García-Bellido, D. (eds.) Advances in Trilobite Research. Madrid: Instituto Geológico y Minero de España, 371–374.

106.                 Siveter, D. J., Fortey, R. A., Briggs, D. E. G., Siveter, D. J. & Sutton, M. D. (2021). The first Silurian trilobite with three‐dimensionally preserved soft parts reveals novel appendage morphology. Papers in Palaeontology 7, 2245–2253.

107.                 Six, A. (1884). Les appendices des trilobites d’apres M. Ch. D. Walcott. Annales de la Société Géologique du Nord 11, 228–236.

108.                 Šnajdr, M. (1987). Zazivací trakt trilobita Deanaspis goldfussi (Barrande) [On the digestive system of Deanaspis goldfussi (Barrande)]. Časopis Národního Muzea 156, 8–16.

109.                 Størmer, L. (1939). Studies on trilobite morphology, part I, the thoracic appendages and their phylogenetic significance. Norsk Geologisk Tidsskrift 19, 143–273.

110.                 Strang, K. M., Armstrong, H. A. & Harper, D. A. T. (2016). Minerals in the gut: scoping a Cambrian digestive system. Royal Society Open Science 3, 160420.

111.                 Stürmer, W. (1970). Soft Parts of Cephalopods and Trilobites: Some Surprising results of X-ray examinations of Devonian Slates. Science 170, 1300–1302.

112.                 Sun, Z.-X., Zeng, H. & Zhao, F.-C. (2021). Digestive structures in Cambrian Miaolingian trilobites from Shandong, North China. Acta Palaeontologica Sinica 60, 166–175.

113.                 Suzuki, Y. & Bergström, J. (2008). Respiration in trilobites: a reevaluation. GFF 130, 211–229.

114.                 Valiant, W. S. (1901). Appendaged trilobites. Mineral Collector 105–112.

115.                 Vannier, J., Williams, M. & Siveter, D. J. (1997). The Cambrian origin of the circulatory system of crustaceans. Lethaia 30, 169–184.

116.                 Vela, J. A. & Corbacho, J. (2009). New trilobites from Upper Ordovician of Käid Rami (Morocco). Batalleria 14, 69–74.

117.                 Walcott, C. D. (1875). Preliminary notice of the discovery of the remains of the natatory and branchial appendages of trilobites. 28th Annual Report of the New York State Regents, New York State Museum of Natural History 29, 89–92.

118.                 Walcott, C. D. (1879). Note upon the legs of trilobites. 31st Annual Report of the New York State Museum of Natural History 31, 64.

119.                 Walcott, C. D. (1879). Note upon trilobites’ legs from the Hudson River Group at Cincinnati, Ohio. 31st Annual Report of the New York State Museum of Natural History 64–65.

120.                 Walcott, C. D. (1884). Appendages of the Trilobite. Science 3, 279–281.

121.                 Walcott, C. D. (1894). Note on some appendages of the trilobites. Geological Magazine 1, 246–251.

122.                 Walcott, C. D. (1894). Note on some appendages of the trilobites. Proceedings of the Biological Society of Washington 9, 89–97.

123.                 Walcott, C. D. (1918). Cambrian Geology and Paleontology, IV. No. 4 - The appendages of trilobites. Smithsonian Miscellaneous Collections 67, 365–456.

124.                 Walcott, C. D. (1921). Cambrian geology and paleontology, IV. No. 7 - Notes on structure of Neolenus. Smithsonian Miscellaneous Collections 67, 365–457.

125.                 Walcott, C. D. (1922). Anatomy of early trilobites. Pan-American Geologist 37, 321–322.

126.                 Walossek, D. & Müller, K. J. (1988). Über die ventralmorphologie und ökologie von Agnostus. Der Geschiebesammler 22, 11–38.

127.                 Walossek, D. & Müller, K. J. (1990). Upper Cambrian stem-lineage crustaceans and their bearing upon the monophyletic origin of Crustacea and the position of Agnostus. Lethaia 23, 409–427.

128.                 Wang, P., Fatka, O., Sun, Z., Budil, P. & Gao, J. (2018). Fossilized gut of the trilobite Lioparia bassleri and the distribution of exceptional preservation in the Cambrian Stage 4-Drumian Manto Formation of North China. Bulletin of Geosciences 93, 491–498.

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