| 词条 | Pycnodus |
| 释义 |
| name = Pycnodus | image = Pycnodus platessus.jpg | image_caption = Pycnodus platessus | status = fossil | fossil_range = {{Fossil range|Late Cretaceous|Lutetian}} | regnum = Animalia | phylum = Chordata | classis = Actinopterygii | ordo = Pycnodontiformes | familia = Pycnodontidae | genus = Pycnodus }} Pycnodus (from Greek for crowded teeth) is an extinct genus of ray-finned fish ranging from the Cretaceous to Eocene periods. As its name suggests, it is the type genus of Pycnodontiformes. The known whole fossils of Pycnodus are around {{convert|12|cm|in|sigfig=1}} long, and have a superficial resemblance to angelfish or butterflyfish. The animals, as typical of all other pycnodontids, had many knob-like teeth, forming pavements in the jaws with which to break and crush hard food substances, probably mollusks and echinoderms. These teeth are the most common form of fossil. Pycnodus fossils have been found in present-day India, Northern Africa, Belgium, England, and Italy, regions corresponding with the Tethys Ocean.[1]References1. ^http://www.geosocindia.org/index.php/jgsi/article/view/68397 {{Portal|Paleontology}}{{Taxonbar|from=Q2844092}}{{paleo-rayfinned-fish-stub}} 8 : Pycnodontiformes genera|Cretaceous bony fish|Paleocene fish|Eocene fish|Late Cretaceous genus first appearances|Lutetian genus extinctions|Cretaceous fish of Europe|Paleogene fish of Europe |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。