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The earliest known venomous animals recognized among conodonts

100%

Szaniawski H.

Acta Palaeontologica Polonica

2009

tom 54

nr 4

Conodonts, a large group of tiny extinct marine animals ranging in age from the Late Cambrian to Late Triassic (ca. 500 to 200 Mya), are usually considered as jawless vertebrates. Their only commonly occurring fossilized remains are minute, phosphatic, teeth−like elements of their feeding apparatuses. In most of the early conodonts the elements were conical and strongly elongated. Many of them are characterized by possession of a deep, longitudinal groove, usually associated with sharp edges or ridges. A comparative study of the grooved elements and venomous teeth and spines of living and extinct vertebrates strongly suggests that the groove in conodonts was also used for delivery of venom. Structural convergence of the conodont apparatus Panderodus with the grasping apparatus of chaetognaths, a group of extant, venomous invertebrate predators of similarly ancient origin, provides additional support for this conclusion.

Late Cambrian acritarch Lusatia: Taxonomy, palaeogeography, and biostratigraphic implications

80%

Albani R., Bagnoli G., Ribecai C., Raevskaya E.

Acta Palaeontologica Polonica

2007

tom 52

nr 4

Intraspecific variability of the herein emended diacrodian acritarch Lusatia dendroidea is described based on late Cambrian (Furongian) well preserved material from Spain, the High Arctic of Russia, and the East−European Platform. L. dendroidea, displays bipolar asymmetric morphology and, as originally defined, consists of three long major processes originating from the “corners” of its vesicle. Specimens with one, two and four major processes are considered to represent morphological variations of the most common three process form. Based on its narrow stratigraphic range, widespread palaeogeographic distribution, and distinctive morphology, L. dendroidea is an excellent guide fossil for the Furongian.

Ograniczanie wyników

2 Acta Palaeontologica Polonica

1 Albani R.

1 Bagnoli G.

1 Raevskaya E.

1 Ribecai C.

1 Szaniawski H.

1 2009

1 2007

Wyniki wyszukiwania

The earliest known venomous animals recognized among conodonts

Late Cambrian acritarch Lusatia: Taxonomy, palaeogeography, and biostratigraphic implications