| Reference Type | Journal (article/letter/editorial) |
|---|
| Title | Homocrinid crinoids from the Upper Ordovician of northern Iowa and southern Minnesota |
|---|
| Journal | Journal of Paleontology |
|---|
| Authors | Brower, James C. | Author |
|---|
| Year | 1997 (May) | Volume | 71 |
|---|
| Issue | 3 |
|---|
| Publisher | Cambridge University Press (CUP) |
|---|
| DOI | doi:10.1017/s0022336000039469Search in ResearchGate |
|---|
| Generate Citation Formats |
|---|
| Mindat Ref. ID | 417316 | Long-form Identifier | mindat:1:5:417316:2 |
|---|
|
| GUID | 0 |
|---|
| Full Reference | Brower, James C. (1997) Homocrinid crinoids from the Upper Ordovician of northern Iowa and southern Minnesota. Journal of Paleontology, 71 (3) 442-458 doi:10.1017/s0022336000039469 |
|---|
| Plain Text | Brower, James C. (1997) Homocrinid crinoids from the Upper Ordovician of northern Iowa and southern Minnesota. Journal of Paleontology, 71 (3) 442-458 doi:10.1017/s0022336000039469 |
|---|
| In | (1997, May) Journal of Paleontology Vol. 71 (3) Cambridge University Press (CUP) |
|---|
| Abstract/Notes | Three homocrinid crinoids from the Upper Ordovician Maquoketa Formation of northern Iowa and southern Minnesota are described: Ectenocrinus simplex (Hall), Drymocrinus strimplei new species, and Sygcaulocrinus typus Ulrich. Ectenocrinus simplex is relatively abundant, geographically widespread in the Appalachians and midcontinent of North America, and long-ranging in time (Middle Ordovician Shermanian to Upper Ordovician Maysvillian). The aboral cup of ectenocrinids underwent transpositional allometry during its evolution so that juvenile cups from the Upper Ordovician Maquoketa Formation resemble the adult cups of ancestral individuals from the Middle Ordovician. Sygcaulocrinus typus exhibits a unique expanded proximal stem consisting of three-to-five large columnals throughout its post-larval development. These columnals are rigidly joined to the aboral cup. Consequently, the proximal generative zone for new columnals is displaced below the proximal part of the stem. In addition, the columnals in the proximal stem of S. typus mainly grow with stong positive allometry with respect to the aboral cup. Essentially, the growth vectors of the proximal columnals converge on those of the aboral cup plates. |
|---|
These are possibly similar items as determined by title/reference text matching only.
