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: 333 MB

Download Project SDD File
Currently Viewing:
MorphoBank Project 2202


    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
    Full membership
    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 views65851
    Project overview2916
    Media views39630Media search (3268 views); M379914 (236 views); M379917 (246 views); M379948 (214 views); M379933 (219 views); M379929 (239 views); M379920 (310 views); M379919 (239 views); M379950 (203 views); M379943 (243 views); M379939 (247 views); M379930 (231 views); M379944 (241 views); M379956 (303 views); M379945 (222 views); M379923 (266 views); M379922 (277 views); M379927 (237 views); M379951 (221 views); M379935 (262 views); M379938 (249 views); M379924 (263 views); M379958 (218 views); M379953 (247 views); M379947 (235 views); M379931 (231 views); M379955 (227 views); M379954 (229 views); M379942 (242 views); M379926 (242 views); M379932 (245 views); M379940 (259 views); M379925 (220 views); M379941 (228 views); M379918 (249 views); M379949 (230 views); M379936 (244 views); M379960 (229 views); M379937 (235 views); M379957 (226 views); M379921 (237 views); M379959 (234 views); M379928 (213 views); M379934 (241 views); M379952 (221 views); M379946 (238 views); M379994 (241 views); M379971 (248 views); M380011 (243 views); M379998 (232 views); M379989 (212 views); M380008 (224 views); M380013 (221 views); M379974 (239 views); M379975 (225 views); M379962 (238 views); M379990 (245 views); M379985 (216 views); M379977 (239 views); M380014 (304 views); M379995 (228 views); M380007 (236 views); M379983 (210 views); M380015 (206 views); M380003 (260 views); M379973 (222 views); M379979 (262 views); M380002 (235 views); M379963 (217 views); M380000 (234 views); M379992 (232 views); M379970 (218 views); M379978 (240 views); M380012 (228 views); M380009 (229 views); M379968 (234 views); M379965 (238 views); M379982 (232 views); M379967 (226 views); M379997 (222 views); M380157 (101 views); M380076 (97 views); M380036 (106 views); M380149 (95 views); M380145 (96 views); M379993 (248 views); M379988 (230 views); M380001 (285 views); M379987 (236 views); M379976 (240 views); M379964 (224 views); M380010 (230 views); M379999 (212 views); M379986 (233 views); M379980 (260 views); M379984 (206 views); M379996 (218 views); M379972 (207 views); M379961 (226 views); M380006 (227 views); M379991 (226 views); M379981 (241 views); M379969 (225 views); M380004 (350 views); M379966 (231 views); M380005 (246 views); M380024 (89 views); M380174 (98 views); M380077 (81 views); M380143 (96 views); M380042 (110 views); M380168 (96 views); M380038 (106 views); M380153 (100 views); M380017 (97 views); M380159 (86 views); M380029 (105 views); M380033 (105 views); M380075 (103 views); M380026 (84 views); M380090 (94 views); M380053 (107 views); M380068 (114 views); M380066 (101 views); M380052 (91 views); M380170 (93 views); M380169 (94 views); M380166 (100 views); M380059 (97 views); M380063 (110 views); M380073 (83 views); M380146 (99 views); M380016 (89 views); M380070 (92 views); M380049 (94 views); M380067 (94 views); M380046 (102 views); M380064 (88 views); M380043 (95 views); M380051 (109 views); M380035 (92 views); M380028 (81 views); M380155 (86 views); M380019 (98 views); M380037 (79 views); M380151 (101 views); M380065 (121 views); M380156 (89 views); M380055 (94 views); M380158 (81 views); M380048 (95 views); M380160 (93 views); M380056 (92 views); M380018 (93 views); M380148 (93 views); M380032 (113 views); M380161 (90 views); M380060 (97 views); M380147 (90 views); M380165 (90 views); M380171 (97 views); M380034 (101 views); M380022 (111 views); M380284 (95 views); M380286 (93 views); M380324 (12 views); M380273 (98 views); M380282 (90 views); M380309 (9 views); M380297 (9 views); M380269 (109 views); M380316 (9 views); M380271 (88 views); M380315 (11 views); M380321 (9 views); M380311 (10 views); M380320 (9 views); M380178 (104 views); M380283 (100 views); M380296 (9 views); M380303 (15 views); M380300 (7 views); M380177 (103 views); M380080 (102 views); M380144 (81 views); M380074 (102 views); M380054 (101 views); M380079 (107 views); M380050 (100 views); M380142 (114 views); M380164 (91 views); M380072 (98 views); M380163 (100 views); M380173 (99 views); M380058 (93 views); M380152 (101 views); M380081 (102 views); M380167 (88 views); M380027 (95 views); M380020 (101 views); M380069 (114 views); M380041 (100 views); M380172 (89 views); M380021 (94 views); M380150 (105 views); M380057 (82 views); M380039 (105 views); M380040 (105 views); M380047 (88 views); M380045 (88 views); M380031 (105 views); M380154 (100 views); M380025 (91 views); M380071 (111 views); M380030 (88 views); M380078 (98 views); M380044 (95 views); M380062 (99 views); M380023 (91 views); M380061 (113 views); M380162 (99 views); M380308 (10 views); M380314 (8 views); M380289 (9 views); M380291 (11 views); M380272 (104 views); M380301 (11 views); M380287 (93 views); M380279 (116 views); M380298 (10 views); M380280 (98 views); M380294 (8 views); M380304 (11 views); M380306 (9 views); M380179 (112 views); M380175 (105 views); M380307 (10 views); M380288 (116 views); M380295 (9 views); M380318 (10 views); M380319 (9 views); M380281 (105 views); M380323 (10 views); M380310 (10 views); M380285 (104 views); M380313 (8 views); M380275 (109 views); M380325 (11 views); M380278 (102 views); M380302 (13 views); M380290 (12 views); M380274 (97 views); M380292 (8 views); M380305 (10 views); M380277 (101 views); M380293 (9 views); M380312 (14 views); M380299 (12 views); M380276 (108 views); M380270 (110 views); M380322 (11 views); M380317 (8 views); M380176 (98 views);
    Bibliography447
    Taxon list4743
    Specimen list18115




    Project downloads

    type number of downloads Individual items downloaded (where applicable)
    Total downloads from project231
    Project downloads166
    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);