Metacarcinus starri

Metacarcinus starri is an extinct species of crab in the family Cancridae, subfamily Cancrinae.[1] The species is known solely from the early Miocene, Clallam Formation and the underlying Pysht Formation deposits on the Olympic Peninsula of Washington state, United States.

Metacarcinus starri
Temporal range: Lower Miocene
Scientific classification
Kingdom:
Animalia
Phylum:
Arthropoda
Class:
Malacostraca
Order:
Decapoda
Family:
Cancridae
Genus:
Metacarcinus
Species:
† M. starri
Binomial name
Metacarcinus starri
(Berglund & Goedert, 1996)
Synonyms

Cancer (Metacarcinus) starri Berglund & Goedert, 1996

History and classification

The species is known from only the holotype female, number UWBM 92012, and five other specimens all of which are currently residing in the collections housed at the Burke Museum of Natural History and Culture in Seattle, Washington, USA.[1] The type specimens were first studied by Ross E. Berglund and James L. Goedert. Berglund and Goedert's species description was published in the Journal of Paleontology in 1996.[1] The specific epithet "starri" was coined by the authors in recognition of David Starr, who collected and donated one of the paratype specimens.[1]

When first described, M. starri was named Cancer (Metacarcinus) starri by Berglund and Goedert. In 1975, J. D. Nations had divided the genus Cancer into four subgenera, including Metacarcinus. This placement was followed until 2000, when the subgenera were elevated to full genera by Carrie E. Schweitzer and Rodney M. Feldmann,[2] making the species' binomial Metacarcinus starri.[2]

Description

The oval carapace, nearly straight posterolateral margins, and chelipeds with spiny upper margins are used as the basis for placing the species in Metacarcinus.[1] In comparisons of overall morphology, M. starri was noted to be most similar to the living species M. gracils, commonly called the graceful rock crab.[1] When published, M. starri was the oldest species of Metacarcinus to be described, being older than M. coosensis, which is known from fossils found in Washington, Oregon, and California. It is also the third species of Metacarcinus to be identified from Washington state fossils. The age and location indicate a possible Northern Pacific origin for the genus.[1]

M. starri lived and was preserved in strata deposited at depths of 50–70 m (160–230 ft), placing them in the lower sublittoral zone. The specimens were preserved in concretions found as loose float cobbles along the Strait of Juan de Fuca shoreline and collected at sites B6133 and B6136. However the individual cobble matrices match sediments found in the upper Pysht and lower Clallam Formations.[1] This species lived with several other crustaceans, including the crab Pinnixa and a mud shrimp of the genus Callianassa. The extinct species Branchioplax washingtoniana was formerly though to also occur in the Clallam Formation with M. starri, however with redefinition of the Twin River Group the sediments, B. washingtoniana has been shown to occur in the older Twin River Formation.[1]

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gollark: I think it's a server thing.
gollark: My slightly newer SomethingOrOther 5000 does too.
gollark: ```Architecture: x86_64CPU op-mode(s): 32-bit, 64-bitByte Order: Little EndianCPU(s): 4On-line CPU(s) list: 0-3Thread(s) per core: 1Core(s) per socket: 4Socket(s): 1NUMA node(s): 1Vendor ID: AuthenticAMDCPU family: 23Model: 1Model name: AMD Ryzen 3 1200 Quad-Core ProcessorStepping: 1CPU MHz: 3338.023CPU max MHz: 3500.0000CPU min MHz: 1550.0000BogoMIPS: 6989.03Virtualization: AMD-VL1d cache: 32KL1i cache: 64KL2 cache: 512KL3 cache: 4096KNUMA node0 CPU(s): 0-3Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc cpuid extd_apicid aperfmperf pni pclmulqdq monitor ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw skinit wdt tce topoext perfctr_core perfctr_nb bpext perfctr_llc mwaitx cpb hw_pstate sme ssbd sev vmmcall fsgsbase bmi1 avx2 smep bmi2 rdseed adx smap clflushopt sha_ni xsaveopt xsavec xgetbv1 xsaves clzero irperf xsaveerptr arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold avic v_vmsave_vmload vgif overflow_recov succor smca```What clear, useful output.
gollark: `lscpu` on Li'nux.

References
  1. Ross E. Berglund & James L. Goedert (1996). "A new crab (Brachyura: Cancridae) from Lower Miocene rocks of the Northwestern Olympic Peninsula, Washington". Journal of Paleontology. 70 (5): 830–835. JSTOR 1306484.
  2. Carrie E. Schweitzer & Rodney M. Feldmann (2000). "Re-evaluation of the Cancridae Latreille, 1802 (Decapoda: Brachyura) including three new genera and three new species". Contributions to Zoology. 69 (4): 223–250. Archived from the original on 2012-12-09. Retrieved 2010-10-01. Also available as PDF.
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