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
    4695262262
    Cornelius Faber
    Full membership
    0000
    Seth Kaufman
    0000
    Jennifer Lenihan
    Full membership
    0000
    Rich Mooi
    Full membership
    0000
    Louis G. Zachos
    Full membership
    0000


    Project has no matrices defined.



    Project views

    type number of views Individual items viewed (where applicable)
    Total project views110559
    Project overview4003
    Media views64365Media search (4871 views); M379914 (421 views); M379917 (420 views); M379948 (361 views); M379933 (357 views); M379929 (406 views); M379920 (515 views); M379919 (437 views); M379950 (358 views); M379943 (398 views); M379939 (382 views); M379930 (387 views); M379944 (386 views); M379956 (455 views); M379945 (351 views); M379923 (420 views); M379922 (436 views); M379927 (388 views); M379951 (382 views); M379935 (397 views); M379938 (386 views); M379924 (417 views); M379958 (401 views); M379953 (410 views); M379947 (385 views); M379931 (394 views); M379955 (377 views); M379954 (365 views); M379942 (372 views); M379926 (387 views); M379932 (399 views); M379940 (409 views); M379925 (367 views); M379941 (372 views); M379918 (429 views); M379949 (392 views); M379936 (396 views); M379960 (369 views); M379937 (377 views); M379957 (389 views); M379921 (410 views); M379959 (359 views); M379928 (363 views); M379934 (387 views); M379952 (370 views); M379946 (376 views); M379994 (386 views); M379971 (351 views); M380011 (354 views); M379998 (362 views); M379989 (321 views); M380008 (330 views); M380013 (348 views); M379974 (343 views); M379975 (339 views); M379962 (350 views); M379990 (365 views); M379985 (313 views); M379977 (344 views); M380014 (416 views); M379995 (363 views); M380007 (355 views); M379983 (315 views); M380015 (323 views); M380003 (408 views); M379973 (340 views); M379979 (378 views); M380002 (356 views); M379963 (335 views); M380000 (355 views); M379992 (334 views); M379970 (385 views); M379978 (342 views); M380012 (352 views); M380009 (340 views); M379968 (330 views); M379965 (360 views); M379982 (331 views); M379967 (330 views); M379997 (329 views); M380157 (174 views); M380076 (168 views); M380036 (176 views); M380149 (170 views); M380145 (167 views); M379993 (392 views); M379988 (358 views); M380001 (391 views); M379987 (340 views); M379976 (361 views); M379964 (356 views); M380010 (334 views); M379999 (349 views); M379986 (352 views); M379980 (383 views); M379984 (324 views); M379996 (332 views); M379972 (310 views); M379961 (343 views); M380006 (333 views); M379991 (368 views); M379981 (360 views); M379969 (328 views); M380004 (481 views); M379966 (366 views); M380005 (354 views); M380024 (158 views); M380174 (171 views); M380077 (151 views); M380143 (165 views); M380042 (182 views); M380168 (170 views); M380038 (181 views); M380153 (176 views); M380017 (168 views); M380159 (166 views); M380029 (176 views); M380033 (183 views); M380075 (175 views); M380026 (154 views); M380090 (165 views); M380053 (180 views); M380068 (189 views); M380066 (170 views); M380052 (163 views); M380170 (169 views); M380169 (165 views); M380166 (175 views); M380059 (171 views); M380063 (184 views); M380073 (157 views); M380146 (174 views); M380016 (158 views); M380070 (170 views); M380049 (167 views); M380067 (168 views); M380046 (178 views); M380064 (162 views); M380043 (167 views); M380051 (182 views); M380035 (166 views); M380028 (153 views); M380155 (159 views); M380019 (174 views); M380037 (155 views); M380151 (176 views); M380065 (191 views); M380156 (161 views); M380055 (163 views); M380158 (157 views); M380048 (171 views); M380160 (166 views); M380056 (167 views); M380018 (166 views); M380148 (166 views); M380032 (187 views); M380161 (161 views); M380060 (169 views); M380147 (166 views); M380165 (167 views); M380171 (173 views); M380034 (177 views); M380022 (184 views); M380284 (175 views); M380286 (176 views); M380324 (27 views); M380273 (174 views); M380282 (167 views); M380309 (20 views); M380297 (17 views); M380269 (189 views); M380316 (16 views); M380271 (170 views); M380315 (26 views); M380321 (17 views); M380311 (23 views); M380320 (28 views); M380178 (184 views); M380283 (178 views); M380296 (22 views); M380303 (28 views); M380300 (11 views); M380177 (200 views); M380080 (175 views); M380144 (149 views); M380074 (172 views); M380054 (178 views); M380079 (177 views); M380050 (170 views); M380142 (187 views); M380164 (158 views); M380072 (182 views); M380163 (173 views); M380173 (167 views); M380058 (163 views); M380152 (179 views); M380081 (174 views); M380167 (164 views); M380027 (168 views); M380020 (173 views); M380069 (187 views); M380041 (173 views); M380172 (161 views); M380021 (168 views); M380150 (181 views); M380057 (154 views); M380039 (176 views); M380040 (177 views); M380047 (160 views); M380045 (161 views); M380031 (189 views); M380154 (176 views); M380025 (160 views); M380071 (186 views); M380030 (160 views); M380078 (171 views); M380044 (164 views); M380062 (173 views); M380023 (161 views); M380061 (188 views); M380162 (178 views); M380308 (19 views); M380314 (14 views); M380289 (18 views); M380291 (26 views); M380272 (195 views); M380301 (22 views); M380287 (172 views); M380279 (202 views); M380298 (23 views); M380280 (177 views); M380294 (22 views); M380304 (19 views); M380306 (23 views); M380179 (199 views); M380175 (176 views); M380307 (27 views); M380288 (200 views); M380295 (14 views); M380318 (15 views); M380319 (15 views); M380281 (190 views); M380323 (20 views); M380310 (28 views); M380285 (185 views); M380313 (17 views); M380275 (187 views); M380325 (22 views); M380278 (187 views); M380302 (23 views); M380290 (22 views); M380274 (169 views); M380292 (16 views); M380305 (13 views); M380277 (183 views); M380293 (19 views); M380312 (28 views); M380299 (17 views); M380276 (181 views); M380270 (190 views); M380322 (23 views); M380317 (18 views); M380176 (184 views);
    Bibliography719
    Taxon list9614
    Specimen list31855
    Documents list3




    Project downloads

    type number of downloads Individual items downloaded (where applicable)
    Total downloads from project367
    Project downloads295
    Media downloads72M379919 (3 downloads); M379923 (3 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 (2 downloads); M379920 (2 downloads); M379921 (2 downloads); M379922 (2 downloads); M379924 (2 downloads); 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);