page_title: List of xiphosuran genera
section_title: Xiphosuran genera
hierarchical_section_title: List of xiphosuran genera / Xiphosuran genera
caption_attribution_description: English: Fossils of Prestwichia anthrax from Coal Brook Dale, England, on display at Gallery of Paleontology and Comparative Anatomy, Paris.
context_page_description: This list of xiphosurans is a comprehensive listing of all genera that have ever been included in the order Xiphosura, excluding purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful, or were not formally published, as well as junior synonyms of more established names, genera that are no longer considered xiphosurans and misspellings. The list currently includes 54 names out of which 31 are considered valid xiphosuran genera.
  As of 2019, there were around 80 extinct species of xiphosurans and 4 extant species of xiphosurans recognized as valid.
context_section_description: † = Extinct
caption: Prestwichia anthrax
exif: {"Image Make": "NIKON CORPORATION", "Image Model": "NIKON D200", "Image XResolution": "300", "Image YResolution": "300", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop Elements 7.0 Windows", "Image DateTime": "2014:06:12 00:21:53", "Image Artist": "Picasa", "Image WhitePoint": "[313/1000, 329/1000]", "Image PrimaryChromaticities": "[16/25, 33/100, 21/100, 71/100, 3/20, 3/50]", "Image YCbCrCoefficients": "[299/1000, 587/1000, 57/500]", "Image YCbCrPositioning": "Co-sited", "Image ExifOffset": "368", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "1204", "Thumbnail JPEGInterchangeFormatLength": "3869", "EXIF ExposureTime": "1/250", "EXIF FNumber": "11", "EXIF ExposureProgram": "Manual", "EXIF ISOSpeedRatings": "400", "EXIF ExifVersion": "0221", "EXIF DateTimeOriginal": "2014:05:17 19:37:18", "EXIF DateTimeDigitized": "2014:05:17 19:37:18", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "4", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "5", "EXIF MeteringMode": "CenterWeightedAverage", "EXIF LightSource": "Unknown", "EXIF Flash": "Strobe return light not detected", "EXIF FocalLength": "82", "EXIF SubSecTime": "87", "EXIF SubSecTimeOriginal": "87", "EXIF SubSecTimeDigitized": "87", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "Uncalibrated", "EXIF ExifImageWidth": "1682", "EXIF ExifImageLength": "1262", "Interoperability InteroperabilityIndex": "R03", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "Interoperability RelatedImageWidth": "2896", "Interoperability RelatedImageLength": "1944", "EXIF InteroperabilityOffset": "1056", "EXIF SensingMethod": "One-chip color area", "EXIF FileSource": "Digital Camera", "EXIF SceneType": "Directly Photographed", "EXIF CVAPattern": "[0, 2, 0, 2, 1, 0, 2, 1]", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Manual Exposure", "EXIF WhiteBalance": "Auto", "EXIF DigitalZoomRatio": "1", "EXIF FocalLengthIn35mmFilm": "123", "EXIF SceneCaptureType": "Standard", "EXIF GainControl": "Low gain up", "EXIF Contrast": "Normal", "EXIF Saturation": "Normal", "EXIF Sharpness": "Normal", "EXIF SubjectDistanceRange": "0", "EXIF ImageUniqueID": "65b448f7eeb614ea68c3a508d09739be", "EXIF Gamma": "11/5"}