Topic
Dinomischus
About: Dinomischus is a research topic. Over the lifetime, 4 publications have been published within this topic receiving 63 citations.
Papers
TL;DR: The presence in both animals of a digestive tract with a potential stomach and anus suggest a grade of organization within bilaterians, but relationships with extant phyla are not straightforward.
Abstract: Burgess Shale-type deposits provide invaluable insights into the early evolution of body plans and the ecological structure of Cambrian communities, but a number of species, continue to defy phylogenetic interpretations. Here we extend this list to include a new soft-bodied animal, Siphusauctum gregarium n. gen. and n. sp., from the Tulip Beds (Campsite Cliff Shale Member, Burgess Shale Formation) of Mount Stephen (Yoho National Park, British Columbia). With 1,133 specimens collected, S. gregarium is clearly the most abundant animal from this locality.
This stalked animal (reaching at least 20 cm in length), has a large ovoid calyx connected to a narrow bilayered stem and a small flattened or bulb-like holdfast. The calyx is enclosed by a flexible sheath with six small openings at the base, and a central terminal anus near the top encircled by indistinct openings. A prominent organ, represented by six radially symmetrical segments with comb-like elements, surrounds an internal body cavity with a large stomach, conical median gut and straight intestine. Siphusauctum gregarium was probably an active filter-feeder, with water passing through the calyx openings, capturing food particles with its comb-like elements. It often occurs in large assemblages on single bedding planes suggesting a gregarious lifestyle, with the animal living in high tier clusters. These were probably buried en masse more or less in-situ by rapid mud flow events.
Siphusauctum gregarium resembles Dinomischus, another Cambrian enigmatic stalked animal. Principal points of comparison include a long stem with a calyx containing a visceral mass and bract-like elements, and a similar lifestyle albeit occupying different tiering levels. The presence in both animals of a digestive tract with a potential stomach and anus suggest a grade of organization within bilaterians, but relationships with extant phyla are not straightforward. Thus, the broader affinities of S. gregarium remain largely unconstrained.
44 citations
TL;DR: The first unequivocal fossil entoproct is reported, a Late Jurassic species belonging to the extant genus Barentsia and described its bioimmured preservation, and comment on its evolutionary significance.
Abstract: It has long been appreciated that the fossil record is strongly biased towards groups with mineralized skeletons. If most or all animal phyla originated in the Precambrian [1], then many softbodied phyla must have long histories unrepresented in the fossil record. Among these are the Entoprocta, a small phylum of aquatic metazoans. The only supposed fossil entoproct is the Cambrian genus Dinomischus [2-4] . However, body size in Dinomischus is at least an order of magnitude greater than that of any Recent entoprocts: D. isolatus from the Middle Cambrian Burgess Shale of Canada is over 25 mm long, and D. venustus from the Lower Cambrian Quiongzhusi Formation of China exceeds 100 mm in length. Furthermore, the "tentacles" of Dinomischus are stiff bracts unlike the flexible tentacles of entoprocts, and other morphological details supporting an entoproct affinity are poorly preserved or lacking. Assignment of Dinomischus to the Entoprocta must therefore be regarded as very doubtful. Here, we report the first unequivocal fossil entoproct, a Late Jurassic species belonging to the extant genus Barentsia. We describe its bioimmured preservation, and comment on its evolutionary significance. Early naturalists included the entoprocts within the phylum Bryozoa (= Ectoprocta), but the many important differences between entoprocts and
18 citations
1 Jan 2006
TL;DR: Dinomischus et al. as discussed by the authors over-allmorphology, epifaunal feeder, primative primative, and primative entoprocts.
Abstract: Dinomischus 是稀罕独居的 epifaunal 暂停 feeder。Dinomischus 的 over-allmorphology 由用包围的一个圆锥形的花萼组成伸长苞和 elongate 茎。内脏的质量和胃囊在身体洞是明显的。Dinomischus 基于形态学和生活方式的类似作为生活 entoprocts 的一位 primative 祖先被解释。以前， Dinomischus 仅仅在二个地区被知道：中间 -- 中间的 CambrianBurgess 页岩生物区系和早寒武纪的 Chengjiang 生物区系。Dinomischus cf 的一个单个标本。D.isolatus Cowry 莫利斯舞， 1977 从 Kaili 生物区系，贵州，中国这里被报导。在 Kaili 生物区系的发现 ofDinomischus 扩大它的地理范围并且显示 rareDinomischus 能更深容忍在中间期间浇背景寒武纪。
9 citations
TL;DR: Dinomischus is a rare solitary epifaunal suspension feeder with a conical calyx surrounded with elongate bracts and an elongate stem as mentioned in this paper.
Abstract: Dinomischus is a rare solitary epifaunal suspension feeder. The over-all morphology of Dinomischus consists of a conical calyx surrounded with elongate bracts and an elongate stem. Visceral mass and stomach sac are evident in the body cavity. Dinomischus is interpreted as a primative ancestor of living entoprocts based on similarities in morphology and mode of life. Previously, Dinomischus is only known in two localities: the mid-Middle Cambrian Burgess Shale Biota and the Early Cambrian Chengjiang Biota. A single specimen of Dinomischus cf. D. isolatus Cowry Morris, 1977 from the Kaili Biota, Guizhou, China is reported here. The discovery of Dinomischus in the Kaili Biota extends its geographical range and indicated that the rare Dinomischus could tolerate deeper water settings during the Middle Cambrian.
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Performance Metrics
| Year | Papers |
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| 2012 | 1 |
| 2010 | 1 |
| 2006 | 1 |
| 1992 | 1 |