Project 2202: A. Ziegler, J. Lenihan, L. G. Zachos, C. Faber, R. Mooi. Comparative morphology and phylogenetic significance of Gregory's diverticulum in sand dollars (Echinoidea: Clypeasteroida). Organisms Diversity & Evolution. (In Press)
Specimen: Mellita grantii (USNM:E26597)

Abstract

Several derived sand dollar (Echinoidea: Clypeasteroida) families are characterized by the presence of Gregory's diverticulum, an accessory organ of the digestive tract. This soft tissue structure is composed of a central tubular caecum that gives off multiple lobes into the periphery of the test. Most notable are the organ's capacity to selectively store sand grains that the animal has taken up from the surrounding sediment as well as the gradual reduction of Gregory's diverticulum during ontogeny. Several aspects of the biology of this structure have remained unexplored, including the organ's precise morphology and structural diversity. In order to provide a concise basis for future histological, physiological, and functional analyses, a comprehensive comparative morphological and phylogenetic study across numerous taxa was undertaken. Taxon sampling comprised over one hundred clypeasteroid species, including various fossil taxa. This extensive dataset permits establishing a concise terminology that incorporates all of the organ's substructures. In addition, three-dimensional models of Gregory's diverticulum are presented that provide an improved spatial understanding of the organ's morphology in situ. The combined data from dissection, X-ray imaging, micro-computed tomography, and magnetic resonance imaging reveal a previously unknown variability of the structure, which also yields several phylogenetically informative morphological characters. Among those sand dollar families that possess Gregory's diverticulum, the organ is present in two distinct shapes, which can be distinguished by the number, shape, and location of substructures. In addition, the data provide unequivocal evidence that Gregory's diverticulum is absent in the extant taxa Rotulidae and Astriclypeidae, but also in the enigmatic Marginoproctus.


Read the article »

Article DOI: 10.1007/s13127-015-0231-9

Project DOI: 10.7934/P2202, http://dx.doi.org/10.7934/P2202
This project contains
  • 262 Media
  • 46 Taxa
  • 95 Specimens
Total size of project's media files: 298.34M

Download Project SDD File
Currently Viewing:
MorphoBank Project 2202

    Authors' Institutions

    • Harvard University

    • Universitaet Muenster (Westfälische Wilhelms-Universität Münster)

    • University of Mississippi

    • Rheinische Friedrich-Wilhelms-Universität Bonn (University of Bonn)

    • California Academy of Sciences



    Members

    member name taxa specimens media media
    notes
    Alexander Ziegler
    Project Administrator
    Last logged in 08/04/15
    4695262262
    Cornelius Faber
    Full membership
    Last logged in 07/05/15
    0000
    Seth Kaufman
    Last logged in 08/04/15
    0000
    Jennifer Lenihan
    Full membership
    Last logged in 06/26/15
    0000
    Rich Mooi
    Full membership
    Last logged in 06/29/15
    0000
    Louis G. Zachos
    Full membership
    Last logged in Never
    0000


    Project has no matrices defined.



    Project views

    type number of views Individual items viewed (where applicable)
    Total project views77815
    Project overview3318
    Media views44845Media search (3678 views); M379914 (286 views); M379917 (297 views); M379948 (239 views); M379933 (246 views); M379929 (275 views); M379920 (367 views); M379919 (304 views); M379950 (232 views); M379943 (269 views); M379939 (271 views); M379930 (264 views); M379944 (273 views); M379956 (327 views); M379945 (242 views); M379923 (302 views); M379922 (306 views); M379927 (267 views); M379951 (253 views); M379935 (291 views); M379938 (276 views); M379924 (293 views); M379958 (270 views); M379953 (279 views); M379947 (267 views); M379931 (261 views); M379955 (253 views); M379954 (258 views); M379942 (266 views); M379926 (275 views); M379932 (280 views); M379940 (282 views); M379925 (249 views); M379941 (255 views); M379918 (298 views); M379949 (259 views); M379936 (270 views); M379960 (246 views); M379937 (264 views); M379957 (254 views); M379921 (275 views); M379959 (253 views); M379928 (250 views); M379934 (274 views); M379952 (255 views); M379946 (265 views); M379994 (277 views); M379971 (261 views); M380011 (261 views); M379998 (252 views); M379989 (232 views); M380008 (240 views); M380013 (237 views); M379974 (257 views); M379975 (240 views); M379962 (259 views); M379990 (260 views); M379985 (229 views); M379977 (256 views); M380014 (324 views); M379995 (263 views); M380007 (252 views); M379983 (226 views); M380015 (224 views); M380003 (301 views); M379973 (238 views); M379979 (279 views); M380002 (252 views); M379963 (236 views); M380000 (251 views); M379992 (251 views); M379970 (256 views); M379978 (257 views); M380012 (252 views); M380009 (246 views); M379968 (245 views); M379965 (259 views); M379982 (248 views); M379967 (244 views); M379997 (236 views); M380157 (117 views); M380076 (112 views); M380036 (122 views); M380149 (114 views); M380145 (111 views); M379993 (288 views); M379988 (250 views); M380001 (303 views); M379987 (255 views); M379976 (262 views); M379964 (244 views); M380010 (245 views); M379999 (231 views); M379986 (250 views); M379980 (280 views); M379984 (230 views); M379996 (235 views); M379972 (227 views); M379961 (248 views); M380006 (248 views); M379991 (263 views); M379981 (255 views); M379969 (243 views); M380004 (383 views); M379966 (256 views); M380005 (266 views); M380024 (103 views); M380174 (114 views); M380077 (95 views); M380143 (111 views); M380042 (126 views); M380168 (112 views); M380038 (125 views); M380153 (118 views); M380017 (112 views); M380159 (103 views); M380029 (123 views); M380033 (124 views); M380075 (121 views); M380026 (100 views); M380090 (110 views); M380053 (122 views); M380068 (133 views); M380066 (117 views); M380052 (108 views); M380170 (109 views); M380169 (110 views); M380166 (117 views); M380059 (115 views); M380063 (125 views); M380073 (98 views); M380146 (116 views); M380016 (105 views); M380070 (109 views); M380049 (110 views); M380067 (111 views); M380046 (119 views); M380064 (103 views); M380043 (112 views); M380051 (126 views); M380035 (110 views); M380028 (96 views); M380155 (103 views); M380019 (115 views); M380037 (97 views); M380151 (117 views); M380065 (135 views); M380156 (105 views); M380055 (108 views); M380158 (99 views); M380048 (115 views); M380160 (109 views); M380056 (108 views); M380018 (109 views); M380148 (108 views); M380032 (130 views); M380161 (105 views); M380060 (113 views); M380147 (106 views); M380165 (106 views); M380171 (113 views); M380034 (120 views); M380022 (128 views); M380284 (112 views); M380286 (111 views); M380324 (18 views); M380273 (117 views); M380282 (106 views); M380309 (10 views); M380297 (10 views); M380269 (127 views); M380316 (10 views); M380271 (109 views); M380315 (15 views); M380321 (11 views); M380311 (16 views); M380320 (13 views); M380178 (121 views); M380283 (119 views); M380296 (15 views); M380303 (17 views); M380300 (8 views); M380177 (122 views); M380080 (119 views); M380144 (96 views); M380074 (118 views); M380054 (119 views); M380079 (122 views); M380050 (115 views); M380142 (131 views); M380164 (100 views); M380072 (117 views); M380163 (117 views); M380173 (109 views); M380058 (108 views); M380152 (120 views); M380081 (119 views); M380167 (104 views); M380027 (112 views); M380020 (116 views); M380069 (129 views); M380041 (118 views); M380172 (104 views); M380021 (110 views); M380150 (122 views); M380057 (99 views); M380039 (122 views); M380040 (124 views); M380047 (106 views); M380045 (105 views); M380031 (124 views); M380154 (116 views); M380025 (106 views); M380071 (128 views); M380030 (105 views); M380078 (115 views); M380044 (111 views); M380062 (117 views); M380023 (108 views); M380061 (131 views); M380162 (118 views); M380308 (11 views); M380314 (9 views); M380289 (11 views); M380291 (17 views); M380272 (128 views); M380301 (12 views); M380287 (113 views); M380279 (141 views); M380298 (14 views); M380280 (116 views); M380294 (10 views); M380304 (15 views); M380306 (17 views); M380179 (128 views); M380175 (122 views); M380307 (18 views); M380288 (133 views); M380295 (10 views); M380318 (12 views); M380319 (11 views); M380281 (127 views); M380323 (14 views); M380310 (14 views); M380285 (123 views); M380313 (9 views); M380275 (124 views); M380325 (13 views); M380278 (125 views); M380302 (17 views); M380290 (16 views); M380274 (115 views); M380292 (9 views); M380305 (11 views); M380277 (124 views); M380293 (10 views); M380312 (19 views); M380299 (13 views); M380276 (125 views); M380270 (126 views); M380322 (15 views); M380317 (11 views); M380176 (118 views);
    Bibliography529
    Taxon list6901
    Specimen list22221
    Documents list1




    Project downloads

    type number of downloads Individual items downloaded (where applicable)
    Total downloads from project264
    Project downloads199
    Media downloads65M379919 (2 downloads); M379923 (2 downloads); M379929 (1 download); M380283 (3 downloads); M379996 (1 download); M379917 (1 download); M379918 (1 download); M380301 (2 downloads); M380302 (2 downloads); M380304 (2 downloads); M380305 (2 downloads); M380285 (1 download); M380286 (1 download); M380299 (1 download); M380316 (1 download); M380318 (1 download); M380319 (1 download); M380321 (1 download); M380324 (1 download); M380325 (1 download); M379920 (1 download); M379921 (1 download); M379922 (1 download); M379924 (1 download); M379926 (1 download); M379977 (1 download); M379976 (1 download); M379975 (1 download); M379974 (1 download); M379973 (1 download); M379972 (1 download); M379971 (1 download); M380048 (1 download); M380049 (1 download); M380050 (1 download); M380051 (1 download); M380052 (1 download); M380053 (1 download); M380054 (1 download); M380282 (1 download); M380281 (1 download); M380280 (1 download); M380279 (1 download); M380278 (1 download); M380277 (1 download); M380276 (1 download); M380275 (1 download); M380274 (1 download); M380273 (1 download); M380272 (1 download); M380271 (1 download); M380270 (1 download); M380269 (1 download); M379997 (1 download); M379998 (2 downloads); M379914 (1 download);